Alcohol is consumed due to many reasons and one is to have a good bonding with friends. It is a way to celebrate or have the courage to say something or do something they don't normally does. It somehow helps you forget or get away with your problems on a short period of time. I guess alcohol servers could somehow control your intoxication once they see you hit that spot.
To be an invincible Russian guy that jumps off a 5 story buildings after 5 drinks!
It is a stimulant which alters your perception of reality. Alcohol can put people in a good mood when they are down.. It can help people sleep or can be a coping mechanism. Everyone has their own reasons for drinking.