Everyone's decision to quit alcohol is different.
I never had that much of a hangover and my alcohol use was a gradual creep up in terms of alcohol over time to where I was very functional. I had other things I generally did with my time, lots of job responsibilities, etc.. My alcohol use progressed when I moved to the area I live in now since it isn't as conducive for doing a lot of outdoor activities. But still, I only drank at night. Some nights I went crazier than others and there were nights I didn't drink.
When I first got to SR, I knew I needed to quit. I knew if I kept drinking, I was going to start having health issues and I didn't want that. I also heard of Deryk Whibley. Hearing of him almost dying at 35 years of age of liver failure shocked me. I didn't think it was possible for someone that young to have liver failure due to alcohol. His story rang a bit too close to home for my comfort, so that also contributed to me quitting. However, I will also admit I was still a bit on the fence as to whether I really wanted to quit or not when I first got to SR.
What has solidified my sobriety is how much happier I am to be out of that cycle, how much less I am stressed, and how much better I feel and look about myself being sober. I hated myself when I was drinking. I couldn't even look at myself.