Rolemodels, double standards, and growing up

So, I was driving Tyler home and we were listening to a lot of Bowling for Soup songs while singing along in the car. This was after a day of hanging out with him, Karah, and one of Karahs friends. Of course the subject of drinking came up, along with other things like clubbing, hooking up, friends, ex-friends, and other not so fun subjects. But while driving, listening to this music, and just trying to have a good time I also started to think about role models and things like that.
Like I have said before, I have no idea where most of my ideologies came from and my questioning them hurts me. So I have no role model that has ever really tried to keep me on the straight and narrow, away from drugs and alcohol, and the other "evils" of society. But when I think about it, I have a favorite band, Bowling for Soup for those who don't know, and they, along with every other band in America drink. They probably also do other things but that's a different story. But my point is that these bands drink, they have songs about it, its socially accepted, and I grew up listening to it, so in all reasonableness, shouldn't I have grown up with these people as a roll model? Shouldn't I have been shown from a young age that its ok?

I don't understand why I like them now, when there are people that I hate just for the fact that they drink or do drugs. I mean, thats one of the main reasons for my dislike of the beatles, that they were so famous and everyone knew they were on all sorts of drugs, but it didn't matter because that's just the era they were in(insert other random excuses here). So why is it ok that a band drinks, and not when other people do it? I guess it comes down to age and laws. I never have a problem with an adult drinking, and yet for anyone under age I pass judgment on a case by case basis, most of the time resulting in me either hating them or trying to ignore the fact.

So, I met someone today, one of my girlfriends friends. He is in the army, and he's a fine guy, we had a fun time hanging out. And when I was making food he made a comment about some recipes that he experimented with while high and that turned out to be really good. Now this is where my mind starts creating double standards. I had been hanging out with him for a few hours before hand, He was in the army, I liked him, and then I found this out and I didn't know what to think. Fortunately he also said something about how he doesn't do it any more or else the rest of the evening would probably have been more awkward, but I really don't know what to think.

Is it ok to have opinions on someone based on what they used to do? do people really change? did he stop because he wanted to or because he had to? is he still that type of person? just so many questions I ask myself and then I just don't know weather or not I want the friend anymore.

God, I'm going to be so screwed when I get to college.