A rather extreme example - but you don't have to do anything you don't want to. Though 2776's list gives a general idea of what goes on at Uni it's not really the definitive case. In my opinion the main thing about uni is you have pretty much total freedom to do whatever you want.
Yeah some students totally let themselves go, on the eating, drinking, shagging, sleeping front - especially in freshers week, though it dosn't have to be like that. At every university there are people who don't drink, people who can actually cook (sadly I'm not one of them) and people who don't have ***Filtered***.
If you don't want to participate in "traditional" student activities you don't have to - from the minute you get to uni, your life will be almost totally under your control. This is sometimes pretty scary in a kind of "is cheese with mold on safe to eat", "how excactly do you pay a credit card bill", "how do you clean last night's dinner out of the saucepan" kind of way. Though most of the time it's pretty enjoyable.
Uni life is unlikley to be completely like what you've heard. we still have to do all the boring things like tidy our rooms, go to lectures, go shopping for food, do our laundary and cooking, though there is lots of time for fun, especially in the first year, so however you get youe kicks, there will be someone else around who shares the same passion.
If it's stories your looking for, head over to http://www.kickupafuss.com/ - but remember uni life isn't always like that.