I've never done any illegal drugs, never smoked anything, never been drunk. I tried alcohol a few years ago (all different kinds), but it tasted so nasty I never got past a single drink. I also try to avoid using medications of any kind unless I need them. Sometimes I'll drink tea with caffeine, but not often, as it makes me feel weird.
In particular, I could never smoke. First of all, just being around it gives me an instant headache. But also, when I was young, we went to the hospital. Outside was a person with a tracheotomy and they stuck a cigarette in the hole in their neck to smoke. So nasty. I am definitely biased against smokers.
I have my own vices and problems, though. I have a sweet tooth. I never went too crazy on sodas, but I have been trying to cut back even there. I could definitely eat healthier choices, and less fast food (and it's sad because I love vegetables that a lot of people can't stand.. it's pure laziness on my part). I could exercise regularly.
Despite my lack of use, I believe in the legalization of all drugs and availability without a prescription. I feel that I could potentially make progress with some of my emotional problems if I were allowed to research and experimentally try various antidepressants and find one that works for me.