Full disclojure (hah): I don't drink though I don't consider myself a teetotaler. I really don't mind what others do to their bodies.
not drink for health reasons
Yes this sounds plausible. Even if the person isn't unhealthy maybe their family history is such that they still don't drink.
have a less active social life etc
As a semi-introvert[1] I always wonder how true this is for the minority of us that much prefer this so called social isolation. I'd take a night alone or with a small group of friends over a bar or conference absolutely every time always. Of course that is assuming there are no other external influences - which is rarely (I'd say never but we're on HN...) the case. All that really matters is whether you are suffering from anxiety rather than loneliness[2].
[2] I can't remember the last time I was lonely or bored. Hmmm, is this really that unusual amongst similar introverts? I just consider myself somewhat curious and self-motivated.
not drink for health reasons
Yes this sounds plausible. Even if the person isn't unhealthy maybe their family history is such that they still don't drink.
have a less active social life etc
As a semi-introvert[1] I always wonder how true this is for the minority of us that much prefer this so called social isolation. I'd take a night alone or with a small group of friends over a bar or conference absolutely every time always. Of course that is assuming there are no other external influences - which is rarely (I'd say never but we're on HN...) the case. All that really matters is whether you are suffering from anxiety rather than loneliness[2].
[1] I'm XNTP somewhere between INTP and ENTP on the meyer brigs http://en.wikipedia.org/wiki/Myers-Briggs_Type_Indicator
[2] I can't remember the last time I was lonely or bored. Hmmm, is this really that unusual amongst similar introverts? I just consider myself somewhat curious and self-motivated.