I drank 6 beers in a couple hours one night at home while gauging the effect it would have on myself. Watched Netflix all the while. The alcohol made it hard to focus on my show, and somehow I woke up the next morning in bed rather than the living room, so there must've been an hour or so that I blacked out. Only felt kinda nauseated for two hours, then I felt fine. Although I enjoyed it a little bit, I don't think I have any desire to ever do it again. Mostly just a sheer indifference to it. The loss of control didn't make anything feel more enjoyable (at least in my controlled setting). I could see myself being slightly more socially loose, but not majorly. My anxiety would be the biggest thing holding me back.
I also know that I if I ever did regularly start drinking or smoking, I'd have the sort of addictive personality that could spiral out of control. I give in to my impulses easily.
EDIT: Oh yeah, I also keep caffeine to a minimum too. I only take it when I really need to stay awake. Don't like the idea of needing caffeine to function, but at the same time I have horrible sleep hygiene and am perpetually sleepy or prone to hypnotic sleepiness so I don't know.