When I drink at uni, I tend to say to myself I drink 2 nights a week, the nights depend on whats on, who goes out etc.
Of course I have drunk on more than this, for example freshers week went way to fast for comfort, however because your at uni doesnt mean its a license to drink all the time. That does cause problems and the stories you hear about spending the entire first year wasted are just stories.
Just be sensible, limit yourself, if you take loads to get drunk, dont do it all the time, just be controlled.