Let's be real here - and no, I'm trying to put this guy down:
He was hardly a qualified teacher. Lots of young people up here go on voluntourism trips to countries in Africa or Asia to teach a couple of months. If you want to try teaching, you can do so locally; There are lots of options.
Musician, sure, it's fun (I've toured in 4 different countries myself playing in band, though 15 years ago now), but it's hard to do full-time.
DL expert would be to push it, there's a long way between being productive and being an expert.
But I'm gonna be frank with you, doing all those kinds of things is possible here because we have a great welfare system. You can work, save aggressively, and do whatever you want.
The unfortunate fact of life here though, is that a lot of entrepreneurs and indie developers (just to pick a few) are funded by welfare checks.