I think of “teetotallers” as being vocal about their abstaining, some to the point of strident abolitionism. Whereas my “sober” friends seem to speak of that more as a personal condition than a zealous cause.

I’ve gotten the sense from twelve-step types of friends that, for them, the “sober” sobriquet goes along with this idea that an alcoholic is never “cured”: that sobriety is always contingent, and that they’re always one drink away from sliding back to “a drunk” again.