I had to be in enough pain to become motivated to stop the first time. I didn't drink every day, but whenever I did, there was usually a loss of control over it.
I knew for a long time that I really should stop drinking before things got worse, but until that happened, I just couldn't get myself to quit.
After I had been stopped for a while (through AA) I came to see that being a practicing alcoholic was actually the tougher, more painful way to live. Being sober became a relief.
The second time I stopped after a 4 and a half year relapse many years later, nothing horrible had happened yet, but one morning after a stupid drunken night something sort of "clicked" in me where I accepted that I couldn't continue on like that anymore. I had reached that point that I knew I wouldn't be able to live with any worse consequences beyond what had happened that night.
I also understood that it was going to be tough to stop, but now I was ready to go through that initial discomfort because I knew from past experience that beyond that, I could have contented sobriety again.