I've recognized it as a truth in genre for a while, having watched friends dither about majors and colleges and coming out, but it's been coming home rather unpleasantly recently. It is deeply embarrassing to find oneself whining like a sitcom teen about how the world is so complicated, especially when one has been part of the working world for a few years.
But there's no dire pressure to grow up: I'm unattached and unfettered by debt or partner or children, so there's not much to do but dither. There's starting to be more fiction aimed particularly at my age group of aimless 20-somethings, things like Jeph Jacques Questionable Content, about us only in a more interesting world, things like the Machine of Death anthologies, people in general, but given at least one certainty: the method of their death.
Not new themes, but new vehicles and voices, which makes them a lot of fun.