I used to think that I was going to drink at one point. I remember thinking, "if I was of age I'd like to buy that lady a drink." But by the time I turned of age and could, I decided I wouldn't touch it. I'd never really been offered alcohol growing up - so maybe that helped settle in the habit. But, I got offered it constantly once I was of age. I declined every time and never sought it out. I don't drink at all and even more so, I don't pay or contribute to alcohol bills directly. If my significant other wants a drink, I tell her to put it on a separate bill.
I used to think that maybe I'd drink but then I'd go to parties and smell beer. And I knew I wouldn't. I'd feel so much anger and resentment as soon as I smelled it. It pulled me back into hell. On top of this, I felt like I was the prime candidate for substance abuse. I have amazing executive control (I have suffered incredible emotional and physical pain over the last decade but I have never shed a tear in that time. Hell, I watched a lot of Disney movies and I still didn't. I do it just to prove that I still have control). You lose some of that control when you drink alcohol (from what I've been told).
So, I just don't. I don't care to know if I'm a jovial or mean drunk. I don't need to know if I'll have a substance abuse problem. Personally, I'd be quite happy if it didn't exist. I wouldn't have to deal with the problems it causes so frequently. I abstain from most other substances as well for similar reasons. (Caffeine really being the only thing that I normally ingest)