I know all you Pgh are going to kill me for saying this, but this is definitely one of the things I miss about SF. At 30, we weren't old and settled, we were still young and hanging out and doing random things. Even those who were coupled made attempts at being social with others, because the social activities weren't all-night drunk parties or getting drunk. It was movies, games, bowling, or just going out to dinner, easily accomplished as units or sets, and mainstays the feeling of solitary age for us all.
Of course, the flipside to that was, we ended up doing that maybe once or twice a month; but that's better than not at all, which is where I'm getting to now. Only when a good friend has entered town once again do we make any attempt at it here.
Or perhaps it's just me being always so reclusive I don't know what's going on anymore. Who can know. Or maybe I'm just being depressed.