Doctor of Finance series

10 Mistakes Worth Making Before 30

Some mistakes are cheaper to learn early. Ten common mistakes of your twenties — the first salary, the wrong job, the loan to a friend — why they happen, and the lesson worth keeping from each.

Himanshu Gulati
A young man sitting by a window in the morning, holding a cup of chai and thinking.

A different kind of list

Part 1 of a three-part series, “Worth Making”: mistakes, risks and relationships.

About the stories: the people below are composites. Their names and details are changed, and each story is built from situations that many of us — and many people we know — will recognise. They are not about any one real person.

Most advice for your twenties is about avoiding mistakes.

Don’t waste money. Don’t choose the wrong career. Don’t trust the wrong people. Don’t quit too soon.

The advice isn’t wrong. But there is something it leaves out: some mistakes are cheaper to learn early.

A wrong job at 25 might cost you a year. At 45, the same decision can touch a home loan, children, ageing parents and other people who depend on you. A few thousand rupees wasted from a first salary can teach you something useful. Learning the same lesson after fifteen years of earning can be much more expensive.

But this isn’t an argument for being careless.

You don’t need to make these mistakes on purpose. The point is simpler: when life gives you one, don’t waste it.

Because the real mistake isn’t always what you did.

Sometimes it’s doing the same thing again after you already know better.

Why early mistakes can be useful

Think of your twenties as a period when some lessons are still relatively cheap.

A wrong job can be changed. A bad spending month can be corrected. A failed side project can be dropped. You also have more time to use whatever you learn.

Research on regret adds an interesting twist. Thomas Gilovich and Victoria Husted Medvec found that people often regret actions in the short term, but over longer periods they tend to regret missed opportunities more.

That doesn’t mean “do everything”.

It means a life built entirely around avoiding embarrassment, failure and discomfort can create a different kind of regret.

The goal isn’t fewer mistakes. It’s better lessons.

A table titled 'Same mistake. Very different price.' At 25: a wrong job costs about a year; overspending a salary costs a few thousand rupees; no savings cushion means a stressful month. At 45: the same mistakes can touch a home loan, children's fees and a team; the habit runs on a bigger income; there are bigger costs and less room to recover. Illustration — general patterns, not data.

Here are ten.

1. Spending your first salary badly

A young man sitting on the edge of a bed in a small flat, surrounded by a sneakers box and shopping bags, rubbing his forehead.

Rohit’s first salary — ₹38,000 — landed on a Friday evening in Pune. He remembers the SMS more clearly than anything he bought with it.

That weekend there was a dinner for the whole flat (“first salary, my treat”), a pair of sneakers he’d been eyeing since college, a new phone cover, two cab rides home at 1 a.m., and a “small” online order. He sent ₹5,000 to his mother and felt like a grown-up.

By the 18th he was borrowing ₹2,000 from his roommate for the electricity bill.

What stung wasn’t the money. It was that when he sat down to work out where it went, he genuinely couldn’t account for about ₹9,000. No single big purchase. Just dozens of small ones that each felt like nothing.

Why it happens: the economist Richard Thaler described mental accounting — we sort money into invisible jars in our heads. A first salary sits in a jar labelled “reward”, and money in that jar feels easier to spend. Small amounts slip through because, one by one, none of them feels like a decision.

What it teaches: the difference between what you think you spend and what you actually spend. Almost everyone’s estimate is lower than reality. That gap is one of the most useful money lessons there is — and it is far cheaper to discover on a ₹38,000 salary than on a ₹3,80,000 one.

Try this: for one month, note every expense — including the ₹20 chai and the ₹50 parking. Don’t judge, don’t cut, just look. At the end, ask one question: “Which of these would I happily pay for again?”

2. Taking a job that turns out to be wrong

The title sounded impressive. The work didn’t. Six months in, Sunday evenings start to feel heavy — and leaving a year later can feel like a “wasted” year.

Why it happens: at 22 or 23, we choose jobs on the information we have — the brand, the salary, what relatives will say at weddings. But you can’t really know what a job feels like until you’re doing it. Herminia Ibarra, who studies career change at London Business School, argues in Working Identity that people rarely think their way to the right career. They test their way there — by trying things and learning from what happens.

So a wrong first job isn’t a failed plan. It’s evidence about yourself. It can tell you that you need to see the result of your work, that you prefer small teams, or that a big brand on your CV matters less to you than you assumed.

What it teaches: career direction often comes from elimination, not certainty. Very few people know what they want at 23. Most people find it by trying something, noticing what drains them, and ruling it out.

Try this: keep two running lists on your phone — “work that gave me energy” and “work that drained me”. Add one line every Friday. In six months, those lists will tell you more than any personality test.

3. Saying yes to everything

Arjun was the person everyone could count on. Cover a shift? Yes. Help a cousin shift house on Sunday? Yes. Review a friend’s presentation at 11 p.m.? Of course. Join the office cricket team, the weekend trek, the wedding committee? Yes, yes, yes.

He was liked. He was also always tired, always behind on his own work, and quietly resentful of the people he kept saying yes to.

The uncomfortable truth was that nobody was forcing him to be this available. The certification exam he’d been planning for two years kept moving to “next quarter”.

The turning point was small. A senior colleague asked him for help with something on a Saturday, and Arjun — for once — said, “I can’t this weekend, but I can do Monday morning.” Nothing bad happened. The colleague simply said, “Monday works.” That was the moment he realised how many of his yeses had never been necessary.

What it teaches: every yes has a cost. Time and energy are limited, and saying yes to one thing quietly says no to something else — sleep, family, your own goals. The people asking usually don’t see that cost. You do.

Try this: before your next automatic yes, ask yourself one question: “What am I saying no to by saying yes to this?”

4. Lending money to a friend — and not getting it back

Two young men sitting at opposite ends of a cafe table in awkward silence, one looking at his phone, the other out of the window.

Karan and Vikas had shared a hostel room for three years. So when Vikas called one evening — “Bhai, just ₹40,000, family emergency, I’ll return it in two months” — Karan transferred it within ten minutes. He didn’t ask questions. That felt like what friends do.

Two months passed. Then four. The calls got shorter. Vikas started taking longer to reply on WhatsApp. When Karan finally brought it up, Vikas said, “You’re asking me now? I thought we were friends.” The money came back in small, irregular pieces over a year and a half. The friendship never quite did.

Looking back, Karan doesn’t think Vikas was a bad person. Neither of them had meant to damage the friendship. They had simply left an important conversation to assumptions — when, how, and what would happen if the plan slipped.

What it teaches: money between people who care about each other needs clearer words, not fewer. Most of these stories don’t break because someone is dishonest. They break because nothing was agreed, so each person filled the silence with their own version.

Try this: before you lend, decide privately: “Is this a loan or a gift?” If you can only afford it as a gift, give it as a gift and let it go. If it’s a loan, agree on a rough timeline at the start — kindly, but out loud.

5. Asking for help too late

Many of us spend days stuck on something one conversation could have solved — staying late, redoing the work, never asking — because asking feels like admitting we don’t belong. Then someone glances at it and says, “Oh, there’s a template for that. Didn’t anyone tell you?”

Nobody told you because you never asked.

Why it happens: we badly misjudge how other people will react. In a series of studies, psychologists Francis Flynn and Vanessa Lake asked people to request small favours from strangers, after first predicting how many they’d need to ask. People expected to ask roughly twice as many as they actually needed to. Others were far more willing to help than people assumed.

What it teaches: asking for help is a skill, not a weakness. Being good at your work sometimes means knowing when someone else’s experience can save you a week. Most people are glad to help — and quietly more worried when someone never asks.

Try this: set yourself a simple rule: if I’ve been genuinely stuck on something for one working day, I ask. Write your question down first, so you can ask it in two sentences.

6. Comparing your life with everyone else’s

A young woman sitting on a sofa in the evening, scrolling her phone with a thoughtful, slightly wistful expression.

A school friend’s wedding in Udaipur. A batchmate’s new car. Someone’s promotion, someone’s Bali trip, someone’s “new home” with a puja photo. Your own life — a decent job, a rented flat, savings slowly growing — starts to look small. And sometimes, the friend with the perfect posts is quietly struggling with the EMIs on the car everyone congratulated them for.

Why it happens: back in 1954, the psychologist Leon Festinger described social comparison — we judge how we’re doing by looking at the people around us. The instinct is old. What’s new is the size of the comparison group. We used to compare ourselves with a few neighbours and cousins. Now we compare ourselves with hundreds of people’s best moments, every day, in our pockets.

What it teaches: you are comparing your full, unedited life with other people’s chosen highlights. And comparison doesn’t only change your mood. It changes your spending — you start buying things to look like you’re doing well, rather than because they make your life better.

Try this: before any purchase over a set amount — say ₹5,000 — ask: “Would I still want this if nobody could see it?” If the answer changes, you have your answer.

7. Starting something and quitting it

The course. The twelve-month gym membership used for five weeks. The blog with four posts. The podcast that never recorded an episode. Many of us have a folder full of these.

Why it happens: often, we’re attracted to the identity more than the activity. We like the picture of ourselves as a runner, a writer, a coder. But the daily work of becoming one is a different thing — and when the picture fades and only the work remains, we stop. That isn’t a character flaw. It’s information.

Notice, too, what you never quit — the thing you keep doing even when nobody is watching or asking. That’s usually a clue about what’s really yours.

What it teaches: the difference between wanting an outcome and wanting the work it takes to get there. Quitting a few things early is how you discover which goals are really yours and which ones you only liked the look of.

Try this: before starting anything new, ask: “Do I want to do this — or do I want to be someone who has done this?” Then start smaller than feels serious. Ten minutes a day you’ll actually do beats an hour a day you won’t.

8. Ignoring your health “for now”

A young man taking a calm early-morning walk along a tree-lined path in a city park.

For three years, Aman’s routine was the same: late nights on deadlines, lunch at his desk, dinner at 11, five hours of sleep, and a promise to start exercising “once this project is over”. Projects never ended. They overlapped.

At 29, a routine health check at work came back with numbers his doctor didn’t like. Nothing dramatic yet — but enough for her to say, kindly and clearly, “You’re young. This is the cheapest time to fix it.”

That sentence stayed with him. Not because it was frightening, but because it was a bill. And like most bills, it was smaller if paid early.

What it teaches: health isn’t a separate project from the rest of your life. It runs underneath everything else — your energy, your focus, your patience, your work. “Later” has a habit of arriving with interest.

Try this: don’t redesign your whole life. Pick one realistic habit — a 20-minute walk, a fixed sleep time, a proper lunch away from your screen — and keep it for two weeks. Then add one more. (And if something about your health is worrying you, see a doctor rather than waiting.)

9. Trying to impress the wrong people

At his first job, Nikhil fell in with a group that spent weekends at expensive bars, wore certain brands and talked a lot about cars. He didn’t particularly enjoy any of it. But they were the “cool” group, and being part of it felt like a sign he was doing well.

He spent money he didn’t have on clothes he didn’t like, laughed at jokes he didn’t find funny, and slowly stopped calling his old college friends because they felt “too simple” by comparison.

When he changed cities two years later, not one person from that group stayed in touch. Two of his old college friends drove four hours to help him move.

What it teaches: who actually likes you, and who likes the version of you that performs for them. The people who stay when you stop performing are the ones worth keeping.

Try this: after time with people, ask yourself: “Was I myself, or was I performing?” Notice who leaves you feeling lighter — and spend more of your time with them.

10. Not saving anything — and then needing it

A young woman sitting alone on a bench in a hospital corridor, looking at her phone with a worried, tired expression.

Ritika was 26, earning well, and spending almost all of it — not recklessly, just fully. Rent, food, travel, gifts, a few nice things. Saving was something she’d “start properly next year”.

Then her father needed an unplanned surgery in her hometown. It wasn’t life-threatening, but there was a hospital deposit, a week of leave, last-minute flights and a dozen small costs nobody warns you about. She had less than ₹15,000 in her account.

She managed — a credit card, a loan from her aunt, a lot of stress. What she remembers most isn’t the amount. It’s the feeling of standing in a hospital corridor, doing sums on her phone, when all she wanted was to be with her father.

What it teaches: a small cushion buys something more valuable than money — breathing room. The point of saving early isn’t to become rich. It’s so that when life happens, you can think about the people instead of the numbers.

Try this: set aside a small, fixed amount every month and treat it as unavailable — even ₹1,000 to begin with. The habit matters far more than the amount. (This is about the habit of keeping a cushion, not about where to keep the money — that depends on your own situation.)

A summary card: ten mistakes, ten lessons worth keeping — first salary: where money really goes; wrong job: what drains you; yes to everything: every yes has a cost; loan to a friend: say expectations out loud; help too late: ask after one stuck day; comparing: highlights aren't life; quitting: outcome vs. process; health for now: later comes with interest; wrong crowd: who stays when you stop performing; no savings: a cushion buys breathing room.

What is not a mistake worth making

Not everything needs to become a lesson. Some things are simply harmful:

  • Borrowing money to impress people.
  • Hiding serious debt from people whose lives are financially tied to yours.
  • Staying somewhere — a job, a flat, a relationship — that makes you unsafe.
  • Ignoring serious health warning signs.

And don’t confuse suffering with growth. If something is damaging your safety, health or dignity, the goal isn’t to “learn from it later”. The goal is to act — and to talk to someone you trust.

The real lesson

Look back at the ten people in this article. Not one of them avoided their mistake. What they had in common is that, at some point, they stopped and looked at it honestly. Rohit worked out where his money went. Sneha wrote down what drained her. Karan decided how he’d lend next time. Ritika started her cushion.

A mistake doesn’t automatically become a lesson. Sometimes it’s just a mistake. The lesson appears only when you look at what happened and change something because of it.

So don’t try to build a life with zero mistakes. Build one where the same mistake doesn’t have to happen twice.

Your 7-day check

Don’t try to fix your whole life this week.

Instead, finish these three sentences:

  1. A mistake I made that I understand differently now is…
  2. A mistake I’m still repeating is…
  3. The one thing I’ll do differently this week is…

That’s enough.

You don’t need a perfect plan. You need one lesson that changes one behaviour.

If one of these made you think, “I’ve done that,” that’s probably the one worth sitting with.

Next in the series: “10 Risks Everyone Should Take at Least Once” — some opportunities only come with a little discomfort.


Sources & further reading

  • Thomas Gilovich and Victoria Husted Medvec, “The Experience of Regret: What, When, and Why”, Psychological Review, vol. 102, no. 2, 1995, pp. 379–395.
  • Richard Thaler, “Mental Accounting and Consumer Choice”, Marketing Science, vol. 4, no. 3, 1985, pp. 199–214.
  • Herminia Ibarra, Working Identity: Unconventional Strategies for Reinventing Your Career, Harvard Business School Press, 2003.
  • Francis J. Flynn and Vanessa K. B. Lake, “If You Need Help, Just Ask: Underestimating Compliance with Direct Requests for Help”, Journal of Personality and Social Psychology, vol. 95, no. 1, 2008, pp. 128–143.
  • Leon Festinger, “A Theory of Social Comparison Processes”, Human Relations, vol. 7, no. 2, 1954, pp. 117–140.

The named people in this article are composites; names and details are changed. Rupee amounts in the stories are illustrations, not data. The “try this” ideas are general habits, not personal financial, medical, legal or tax advice. This article is for education and reflection only.

Himanshu Gulati
Himanshu Gulati

A Chartered Accountant studying psychology. I write about the habits, feelings and relationships behind everyday money decisions. More about me

Education only. Not financial, tax or investment advice. Spotted a mistake? Tell me in the comments below and I’ll correct it — see editorial standards.

Comments

Every comment is read before it appears. Replies are my own thoughts, not advice for your situation.

  1. Kripa

    I think the one about starting something and quitting when it gets boring hit me the hardest. I’ve realised that I sometimes get interested in something initially, but when it starts feeling difficult or boring, I start questioning whether it’s actually right for me. This article made me think that maybe I need to give things enough time before deciding.

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