I'm new here but If I can put in my two cents. Im 25 and I have pretty much completely stopped drinking. The only time I drink is when I'm with old friends and if I drink its maybe like 3 beers tops. This hasn't affected the way people perceive me at all. If anything its an advantage, you are the sober guy, you can drive a car, sharper wittier, also I like to joke around and do stupid stuff when I'm out at the bars, when people realize I'm not even drinking they are instantly drawn to me. Explaining why you don't drink is an easy in to a conversation too. Its good to still act curious about alcohol though. Guys will try to get you to drink, but girls even more, and they will use their looks to try to see if they can be the one to "change" your mind. Ask to try a girls drink if it looks colorful and expensive follow it with a funny face and "Woa,I think I'm gonna stick with my water tonight hahaha!" It shows that you have got nothing to prove with your drinking and it sets you apart from the bro's doing kegstands etc.