crack is awfully moreish
you probably won't miss out on much fun, IF (and that's a big if) you still do all the social going out activities everyone else does. i actually applaud non-drinkers, on the odd night i've tried to stay sober i've got to maybe about 1 o clock, got bored and decided to get in a massive round just for me.
one place where you probably won't be able to avoid is sports social events, which revolve heavily around drinking. if anyone tries to tell you otherwise, then they are lying. the social aspect of sport is hugely alcohol orientated. i know plenty of people (me included for a while) who are members of sports clubs just for the social aspect. and by social aspect i mean chopping pints.