Thanks @Moose72!

Yes, I can see how getting into something might give you meaning. As far as I'm concerned, it's still a question of usefulness. Providing a service in exchange for acceptance. Once the service stops, so does the acceptance.

As for kids, yes, we'll always be parents but our utility diminishes over time. Eventually, they won't need us because they'll be financially and emotionally independent, at which point I've become useless, so they carry on and what's left?

Yup, we could ask for nothing more than their independence, that's a great feat and accomplishment. Being discarded at that point? That's hard after all that investment in terms of money and pure giving of one's life.