I knew that I had a problem for a long time, but I was in denial until a couple years ago. Normally I would blame it on my circumstances, saying to myself that I was drinking because of depression, trouble at work, or difficulty with a relationship. It kind of sank in gradually over time. There was never a sudden moment of clarity, so much as slowly admitting to myself that drinking is no longer the result of my issues, it is now the cause.
I had a few moments where I tried to remember the longest period of time where I was not drinking at least 2 or 3 times a week, and I realized that I could only count a handful of instances, and each of them were for periods of less than 3 or 4 months.
It goes without saying that I've also felt a lot of guilt for the things I did and said to my family and girlfriends over the years.