Ask HN: My dad just retired. What should he do?

My dad is a Physics grad who has spent his entire life in Accounting and Taxation. Is fairly OK with tech but took early retirement since he wanted to "try something else". This has mainly resulted in Netflix so far.

I am seriously not sure how I should advise him on what he should constructively do next to remain engaged and active (mentally and physically).

A lot of my friends are in a similar situation with their current parents. Feel like for this is starting to become a problem for all recent retirees! (Just tech savvy enough to browse apps/web but not motivated enough to learn programming)

P.S. We end up going into these deep topics like Universal Basic Income where his perspective from age and experience brings new dimensions https://twitter.com/jharohit/status/1097852468048814080?s=19