Far less scientific, and possibly untrue, but I've heard it described as the difference in having a drink every day, and needing a drink a day. If you can't sk

Far less scientific, and possibly untrue, but I've heard it described as the difference in having a drink every day, and needing a drink a day. If you can't skip that one drink, you've got a problem. (My brother likes to quote that. I think it keeps him believing he's not an alcoholic, which he definitely is. He drinks very heavily 2-4 nights per week, and skips the other nights.)