I'm 23, have never smoked or done any "recreational" drugs. I drink maybe 3-4 beers on a heavy WEEK. Never drink when I'm not at home unless I'm staying over somwhere, if I have to drive I won't even have 1 beer. On a rare occasion I might have a martini when I go out, but only if the wife doesn't order a drink, and I let her drive home. Not that I can't hold my liqour, I just don't screw around, being a driver for a living.
Both my parents are Alcoholics, wich was the main factor that led to their divorce when I was very young. So having that in the family I'm carefull about not over doing it, I can count on one finger the number of times I've had more than one beer in a night.