I have to put a vote in for DB's sliding scale theory. The BB allows that 'real' alcoholics can start of as moderate drinkers.
This is a question that pops up for me now and then though. Sometimes I feel like the concept of a 'real alcoholic' is divisive, because maybe I'm not one. Maybe I was just a hard drinker. But then I have to remember that the only requirement for membership to AA is a desire to stop drinking. It doesn't matter where you are on the scale.