I love what I'm doing now and it fits a lot of the themes people have already identified - I'm a private music teacher. Set my own hours, flexible if I need it to be, and I find I get energy from my students. I have several times been having an off day and had to push myself to be ready for an afterschool student, then when lessons finish I'm feeling much better.
My absolute downfall is admin - to the extent that I'm regularly behind in invoicing parents so as to actually be paid for what I'm doing. I had great thoughts that by the end of last week I'd have emailed for preferred lesson times for the new year, so that this week I could set up my new timetable - has it happened? ....
Interestingly, I deliberately didn't consider studying music from school, as I knew that it would spoil it for me, and at the time there were other things I was definitely better at. But teaching (or explaining things) has been a general theme throughout and after my first career directions proved incompatible - for me - with small children, I eventually fell into music teaching, and have done it for several years now albeit still fairly small scale.
Reading one of the lottery threads the other week I realised that one of the things I'd do, if money was no object, was set up ways to teach more students who couldn't otherwise afford lessons. That's how much I enjoy it.
But I also thrive on variety; a CPD course I do has prompted me to look up our local psychology research department and maybe next year some time I'm going to talk to them about possibilities for developmental research and music learning, see what might interact with their current projects and interests.