Teens drink for many reasons, but I'll only list three. The first reason is that they think it's a rite of passage, and part of becoming an adult. This is a bad reason, because my parents, and the rest of the adults in my religion don't drink. You can be an adult without drinking. Another reason is because they want to fit in and feel confident from the alcohol. This isn't a good idea either, because if all your fronds drink, they'll probably betray you because of being drunk. You could always find new, no drinking friends too. Finally, teens drink to escape their feelings. They might feel sad or depressed in the real world, and drink to have a good time and escape them, but the alcohol just intensifies this depressed feeling. Also, if you do something stupid, they make you have more guilt, so you feel even worse. Also, if you drink you can do things you wouldn't normally do and offend people you care about. Driving while drinking can lead to crashes, serious injuries, and death.
Here's another lego picture : a drunk person trying to beat up his friend.1