Peculiar artifact? Are you forgetting all the people who retired from mining coal, building cars, or running plumbing? It's not weird that seventy year olds would prefer to stop doing those things. I don't know that many people who would claim blasting ore underground is their enjoyment.
The work/retirement dichotomy is such a weird and peculiar artifact of the 1950s US middle-class nuclear-family milieu.
That's gone.
For the rest of us, it's just...live your life, until you don't.
(viz. Below the fold: "Buffett remains as chair...")