ColeMcdoi said:
They also say that they are very social when they are drunk but I doubt that lying wasted on the floor or barely standing on their own is "social".
You don't have to get wasted whenever you drink though. It's all about moderation. I, for example, normally have a really hard time being social. Before I started drinking, I would normally only sit there, observing, when I was at a party. It got really depressing to see all the other people having fun while I was sitting there in the couch all by myself, not being able to reach out to anyone.
However, after a few drinks, I am somehow magically relieved of most all my social problems. I can easily talk to people, I get less of a problem with physical contact, and silences don't feel awkward.
However, I do think 15 is too early to start drinking. Most 15 year olds aren't mature enough to handle drinking responsibly. They will normally drink past their comfort zone in order to brag about it to their friends. This type of person, incidentally, is a kind I hate.
Edit: As for what you can do about it... There's nothing you can do. Morons will be morons. If they try to pressure you into drinking, you should just decline; but in case you can't bring yourself to refuse: If you do not want to get drunk, but still feel you have to drink something because of pressure; try to stand up and move around while you're drinking. I had the strangest experience a while back, you see. I was drinking while standing/walking around the house of a friend. It came to the point where I had drunk an amount that I knew should have made me rather inebreated. Enough so that I should have a bit of trouble standing on one foot. However, I was completely sober. I tried testing it by balancing on one foot, touching my nose and doing pirouettes up a staircase. Everything went swimmingly.
So, try to move about and drink water if you are pressured into drinking.
Tl;Dr: You shouldn't drink because "it's cool", or to feel like an adult. You should drink because you enjoy it, and you should do it in an environment where you are comfortable. A good idea might be finding someone who can actually enjoy drinking in moderation, and drink with them. Perhaps have some cheese and wine. (Stay off the blue cheese though. That stuff tastes horrible.)