I read on HN a comment to the effect that to feel better in your 60s means you must do somethings in your 50s. The things you need to do in your 50s also make you feel better in your 50s. And to be able to do these things in your 50s requires you to do somethings in your 40s - which also make you feel better in your 40s.

Feel better meant being more active and more social. Obviously my recollection lost all the "literary" qualities that comment had - but I like its message.