I have a colleague who completely avoids alcohol. No particular reason for it other than one day he decided to do it because his friend wanted to do it. His friend didn't keep it up, but he did for ~30 years now. I have nothing for or against alcohol and I like some drinks now and then (mostly avoid beers, just don't like the taste).

I have to respect this guy that he keeps it up so long, even though he has nothing to gain or lose from it. I would have figured at least one day, what the heck, it's not a big deal, not doing anything bad or anything. But he decided he won't drink, so he doesn't. Mad respect.