I kind of feel odd commenting in here, since I'm only 20, but because of my personality I think I understand.
I am currently a junior in college, but the thing is that I don't drink, and thus I don't "party." Which kind of sucks because if you didn't know, there really isn't too many people at college who don't party. It's also not that I have a problem with having friends who drink and party, it's just impossible to hang out with them because of it. It's also no just my college friends, but a lot of my friends from high school. Luckily I have a handful of good friends that either don't drink or drink casually that I hang out with a lot.
I realize my situation is probably much different, but I think I at least understand a little bit.