I'm currently reading Quentin Crisp's radiant autobiography, "The Naked Civil Servant", which I strongly recommend. Here's a wonderful quote why Crisp didn't drink alcohol:

For about twenty years I lived in a state of intoxication with my own existence and, perhaps for that very reason, excess of alcohol was one of the extremes to which I felt no urge to fly. I asked many people why they drank so much but never received an explanation that I fully understood. It was the tales of their escapades while under the influence of drink that brought me nearest to comprehending their need for it. It seemed to give them a few hours of freedom from rates which, during the rest of their lives, they reluctantly obeyed. If this was true, then in the example of my life lay a cure for drunkenness, though it was hardly an answer which Harley Street would have approved. The prophylactic is, never to conform at all.