Doctor. Still want to explore "systems" to diagnose issues and build plans for improvement. When I was 45, I did briefly consider making the switch
I became an electrician, instead, with stints IBEW and self-employed residential. Lots of money-making opportunities, but lots of unlicensed competition from handymen that "know just enough to be dangerous" — most customers only care if the light turns on, not that it's long-term safe.