The worst part about money mistakes is that you don’t realize they’re mistakes until years later. I spent my early twenties making decisions that seemed fine at the time, but cost me tens of thousands in lost compound growth, interest payments, and opportunities.
1. Carrying High-Interest Debt Like It Was Normal
I had a credit card at 23% APR that I didn’t pay off for three years. That $3,000 purchase ended up costing me $4,200. Every month you carry a balance at 20%+ interest, you’re losing 1-2% of that balance to the credit card company.
What I’d do differently: Attack high-interest debt like it’s on fire. Pay 5-10x the minimum. The time value of money works against you when interest is that high.
2. Not Opening a Roth IRA Until I Was 28
This one hurts. I had no excuse—I had enough income, but kept “meaning to get around to it.” That five-year delay cost me approximately $50,000 in future retirement savings (assuming 7% annual returns).
The magic of compound growth is that the earliest money you invest does the most work. Money at 23 has 42 years to grow. Money at 28 has 37 years.
What I’d do differently: Open a Roth IRA the moment you have earned income. Even if you can only invest $50/month, open it. The account is free.
3. Buying Things I Didn’t Need With Money I Didn’t Have
I financed a $2,000 camera I used twice. I took out a personal loan for a “business course” that taught me stuff I could have learned free on YouTube.
The pattern was always the same: I wanted it, I could afford the payment, so I did it. I never did the math on the total cost.
What I’d do differently: Simple rule: if I can’t pay cash for it in the next 30 days, I don’t buy it. The friction of “do I really want this enough to wait a month?” filtered out 80% of garbage purchases.
4. Not Negotiating My Salary
I was afraid to ask for raises. So instead of making $50k and negotiating to $55k, I job-hopped every few years to get bumps of $2-4k.
If I’d simply asked for $1,000/year raises, I’d have been making $10,000+ more per year by 30. The math is so much better than job hopping.
What I’d do differently: Have the “raise conversation” annually. Worst case: they say no and you ask again next year.
5. Not Tracking My Money At All
I had zero idea where my money went. The first time I tracked my spending, I found $600/month in waste: subscriptions I’d forgotten about, duplicate memberships. That $600/month, invested at 7% for 20 years, is $274,000.
What I’d do differently: Track everything for 30 days. That one month of awareness usually leads to finding 5-15% in cuts.
The Pattern
Most of these mistakes came from the same root: I didn’t think small decisions mattered. But small decisions compound, especially with money. The good news? You can fix most financial mistakes. It just takes time and consistency. Start today, even if you’re behind.