Yes, social factors increase usage of all these things and people will force themselves to do it, but that's not universal.
I also love the flavor of smoking tobacco products (including cigarettes), although I only smoke a few times a year for social, health, and convenience reasons.
obviously, tastes vary strongly, so both groups must exist.
in my case i escape the peer pressure by discovering that strong coffee actually made me sick, and i used that as an excuse to reject coffee even in situations where it was considered impolite to reject an offer when i was visiting people.
Now I've "matured" and realized coffee is a drug. Or, if you will, a medicine. You don't take medicine because it tastes good, but because the effects are, on balance, good for you.
probably things like mild peer pressure, fitting in with the grown ups, etc, much like smoking, and maybe even drinking.