Fully agree with the second point. For me, learning another language (and a hard one for English speakers) has given me a new outlet for my brain and something difficult and rewarding to do.

In the past I would've given the majority of my "brain power" to just work, and while I have enjoyed that at certain points when I've learnt a lot, I feel like it is not great for mental health and well-roundedness long term. Especially as you say caring about something you don't own where more work =/= more gain.