Trying to describe the process of becoming an alcoholic is like trying to describe air. It's too big and mysterious and pervasive to be defined. Alcohol is everywhere in your life, omnipresent, and you're both aware and unaware of it almost all the time, all you know is you'd die without it, and there is no simple reason why this happens, no single moment, no physiological event that pushes a heavy drinker across a concrete line into alcoholism. It's a slow, gradual, insidious, elusive becoming.
