I needed to believe that it was possible. For whatever reason, I thought that a sober alcoholic was just always on the verge of relapse, that nobody ever truly got sober. It's how it's often (always?) portrayed in movies or novels. Alcoholics relapse, period.
I thought it would lead to a dull life, full of constant fear, at best. A futile attempt at "normalcy". I had seen my father die of liver failure, relapses don't get more definitive than that.
Once I found evidence (which is a long story) that this view is wrong, that it is possible, that you can be happy and comfortable in sobriety, I went for it with total dedication.