seconded.

When I was in college I worked full time but used credit cards the wrong way (and paid for it over the course of a few years).

Now just about everything goes onto a credit card (NOT a debit card) and it's paid off monthly.

Having a good credit opens a lot of doors and helps lower a lot of costs. Car insurance -- a huge factor in this is your credit score. Security clearances -- bad credit = harder to get security clearance.

Also if you ever need to self fund a start up, having good credit is important.