..I realized that especially if you don't have kids and don't have adventures...what the hell are we doing all this for??
Hit the nail right on the head for singles with no offspring, though some singles may be into collectibles or other hobbies requiring square footage. Even adding biking and maybe snowsports again there goes the gear closet, think I'll need a bigger square footage (paraphrasing Jaws).
I think most keep working out convention, never getting out of debt, but my thought is also a part knowing life circumstances can change, so keeping the resume updated, etc…. When to at least semi-retire is when kids are no longer an option (not relevant to the story but probably to those hitting mid-40's). That said, society assumes everyone has kids, spouse, house, car(s), and time-shares for vacation… (directly or through child support), so the economy has been set up that way (along with traditional societal expectations).