I personally have had a patchy relationship with alcohol over the past few years. For example, I continuously ask myself "do I drink too much?" - several nights a week I will have about four bottles of beer. At my worst I was having it about five nights out of seven; that clocks up to 30 units of alcohol. Now, I still have maybe three nights where I drink and I still question if it's a dependance.
But I say "Today I'm having nothing". And I don't have any alcohol. Nor do I the following day, or the next. Then, the next night I might say "I've not had any for a few days, I'll get a couple of bottles for tonight!" and maybe neck four or five, and due to my low BMI, it knocks me for six.
I guess it's speculative. It's dependant on the individual. But certainly in my circumstance, despite now being out of the "dangerous" category of consumption, it's still not what you'd call a "normal" relationship.