Few mistakes are more difficult to erase than money mistakes. The errors of youth have a way of haunting us long after we’ve changed our ways and become models of responsible personal finance. If you’re in your 20s, look ahead and make life easier for your 30-something self. Here are eight money mistakes at 20 that will land you in debt by 30.

1. Amassing huge student loans

According to Student Loan Hero, today’s average student loan borrower will graduate owing $37,172. What makes student loan debt particularly dangerous? First, most loans have variable interest rates. When rates increase, so do your payments (try budgeting around that). Second, student loan debt can’t be discharged in bankruptcy. If you default, the government can garnish your wages, take your tax refund, and even dip into your Social Security payments in retirement. (See also: What Really Happens When You Don’t Pay Your Student Loans)

2. Carrying credit card debt

With high interest rates, late payment penalties, and other fees, a modest credit card balance can quickly become a major problem. People who overspend in their 20s can easily rack up huge debt loads by their 30s — a situation that forces many to delay homeownership, toil away at jobs they dislike, and live with constant financial stress. Avoid the drama of consumer debt. Adopt a strict policy of paying off your credit balances in full each month. (See also: The Fastest Method to Eliminate Credit Card Debt)

3. Ignoring your credit score

Your FICO score is your GPA of adulthood. That magic number affects everything from loan eligibility and interest rates to employment opportunities. Since rebuilding a low credit score can take years, you can’t afford to ignore it. Just imagine getting stuck with a…