If you don't know what your passion in life will be, but have in inkling, this is a great time to find out: Make a serious go at doing whatever it is that you think you might be interested, and see how you like it.

I knew a woman in college who thought she wanted to be a clinical psychologist until she volunteered at the crisis hotline and spent a summer working at a summer camp for kids with problems. If she'd gone ahead and gotten an advanced degree in the field before she realized that she didn't enjoy the work, she'd have been even further behind.

As for making sure that you spend some time enjoying yourself in college, my experience is that the amount of money you have has only a little to do with how much fun you have. The person I remember from college as having the most fun of anybody had a discretionary budget of just $10 per term. Mind you, this was back in the 1970s when $10 was real money--you could get a small pizza and two sodas for $3, so she had enough to take someone out for pizza three times over the ten-week term, and still have $1 for some extravagance. I had perhaps ten times the available cash, but I don't think I was any happier.