It's pretty easy to hang out with drinkers when you drink. Grab a glass, shoot the shit.
But it's hard to hang out with smokers and drinkers when you don't drink or smoke. Those who smoke or drink are the vast majority of the adult US population.
It's especially hard when you're not religious, as most of the teetotalers seem to be religious. Finding non-smoking, non-drinking, religiously tolerant peeps as an adult is so, so tough. It's like, choose one (or more) - drinking, smoking, institutional religion. Those are your options if you want to be a social adult.
It doesn't seem like it should be this way, but it seems to be, across countries and cultures.