After 15 years in finance — working with companies, managing budgets, and watching how people at every income level handle money — the same patterns show up. The mistakes are not random. They are predictable. And they are avoidable, if someone points them out before you make them.
Here are the five I see most consistently among people in their 20s, and what to do instead.
The luxury car lease is the most common and most expensive early mistake I see. You just got your first real paycheck and the dealership is happy to put you in something impressive. The monthly payment feels manageable. What you are actually signing up for is a permanent car payment, a depreciating asset, insurance costs calibrated to an expensive vehicle, and the psychological commitment that makes it hard to step down when the lease ends. I have watched people spend $700 to $900 a month on a car at 24. That is $8,400 to $10,800 a year, every year, that could be compounding in an investment account instead. Buy a reliable used car and invest the difference. The math over 10 years is not close.
This is lifestyle creep, and it is the reason many people with very good incomes still feel financially stressed. Every raise triggers an upgrade: the apartment, the car, the restaurant tier, the vacation category. Each upgrade feels justified because the income supports it. The problem is that net worth only grows if there is a gap between income and spending. Close that gap and you are on a treadmill — better-dressed than before, but not ahead. Treat every raise as a savings event first. Let the investment accounts grow before you decide what to upgrade.
Delivery apps, meal kits, car services, convenience everything. The pitch is that your time is valuable. At 23, you have more free time than you think — and more than you will have in five years. The delivery culture in particular is expensive in ways that compound quietly: $18 meals become a daily habit, and $6,500 a year in delivery fees is real money that feels like nothing because it arrives $18 at a time. This is not about deprivation. It is about recognizing that the "your time is valuable" argument is designed to sell you something, and being honest about whether the math actually works at your stage of life.
The best investment most people in their 20s can make is in their own skills and earning capacity. A certification that costs $2,000 and takes six months to earn could increase your salary by $10,000 a year for the rest of your career. An MBA from the right program, even a part-time one at night, can open doors that double your earnings within five years. Getting genuinely good at your craft — better than your peers at your level — is the single most reliable path to higher income. People who invest this way early rarely struggle financially later. People who do not, often plateau.
There is always a new thing — dropshipping, crypto trading, flipping sneakers, some app that promises passive income. Most of these go nowhere, and the time spent chasing them comes at the direct expense of the thing that actually pays: getting exceptionally good at your primary career. The person who spends 20 hours a week trying to build a side hustle while doing mediocre work at their day job is losing on both fronts. The person who spends those 20 hours becoming the best person in their role compounds that expertise into promotions, offers, and eventually the leverage to earn significantly more. Mastery in your primary field is the most reliable wealth-building side hustle there is.
Beyond the five: living far from your job to get more space is a real cost when you factor in commuting time and expense. Not networking while you are in environments rich with people to learn from is a compounding mistake — relationships built in your 20s become referrals, opportunities, and collaborators for decades. And thinking too short-term in general: every financial decision you make in your 20s has a 40-year compounding effect. Very few things deserve to be optimized for this month.
The five mistakes are avoidable. The car, the lifestyle creep, the convenience spending, the underinvestment in yourself, and the distraction of shortcuts — each one is a decision you get to make consciously. The people who make the right calls early are not typically smarter or luckier. They just had the information sooner. Now you have it.