There's work that is completely unfun, and fun stuff that can be done at work. There's even stuff which, if done often enough, can be tentatively classified as work, or even a career, just by default. Someone who is independently wealthy but paints for the joy of it might still be called an artist even if they never sell a single painting.

Ideally, there would be something that you really like doing, you probably wouldn't get bored with, and which it's technically possible someone might actually pay you to do.

Me, I like designing random stuff to solve problems. I'm no engineer, and actually building half of it would drive me nuts from boredom, but I like gnawing on conceptual roadblocks. I actually have a weekly meetup group which gets together to do this commercially, and it may end up making me beer money via part-ownership and patents on a couple dozen projects, but at the moment I do it for free because I like bashing away at a different problem every month and batting ideas back and forth between myself and the other group members.

I could probably see myself doing something similar for music and drawing, as well, if I ever bothered to learn how to do it better. Not making an entire career out of it, but I'd be happy to play the odd gig or sketch up the occasional commission for cash in hand.

Heck, I'm looking at doing something similar for computer support in the local area. I'm fine with solving a handful of things a week and getting a meal or gas money out of it.