I have fallen into the trap of credit cards already and it's only my freshman year of college! Growing up I never understood why people have credit cards, because it seemed dumb to me to spend money you don't have. But when I was going to rent an apartment, I needed to have a credit score, so I took the plunge and got a credit card. When I had no other money, I charged my credit card with small dumb things like 7-eleven and pizza, but it really added up. The best thing I've learned from having my credit card so far is to pay it off whenever you have a couple extra dollars to lower your balance. Don't just pay the minimum when your payment is due because it'll collect interest and become OUT OF CONTROL CRAZY!!!