I just heard a true story of a guy who had a lucrative career in quantitative finance but then, when he was in his early forties, decided to abandon it and pursue a degree in the history of Asian art. Because that's what always interested him the most.
I really admire this kind of people. And, of course, this isn't about leaving quantitative finance for the history of art. I would admire this person just as much if he left an academic career to pursue his dream of becoming a quant. It's just great to see that people don't settle for things that have stopped fulfilling them. It's never too late to drop everything that doesn't make you happy and start anew. Miserable, boring relationships, unfulfilling jobs that go nowhere, hobbies that bring no joy any longer - what's the point of allowing your one and only life to be wasted on such things?