After my vow to never drink again, I lasted 14 days. It was a clear and conscious decision to drink. I too was baffled at my fall. What my relapsed proved to me was the insanity of alcohol and any thoughts of drinking again, any at all, was insane thinking. Alcoholics can't make clear and conscious decisions regarding alcohol. I wasn't a normal drinker, and I wasn't going to turn into one no matter how much I wished it so. I accepted never drinking again.
I've been sober since that relapse.