The first time I quit for a long period of time, I just realized that I was sick, scared, and that nothing in my life was going to work out if I kept drinking. Plus I was physically wrecked. I was on unemployment at the time so I made sobriety my only goal for a full month.
I did relapse after eight months, not because I think I was doing it wrong, but because I guess I'm the type of person who had to learn first hand that a period of sobriety doesn't cure the disease. I had another two years of struggling hard. In the end I went to rehab because I knew I had gotten to the point where I no longer had the strength to look out for my own best interests. And I fell back on my family. Those two things saved me.