At 64 years old, I have had 9 weeks off from playing since right after my 11th birthday.
Every once in a while, I get down in the dumps. Right now, for instance, I'm not recovering very well from damage to my left hand...nerve damage...not good for a "walking left hand bass" B-3 player.
But, every time I get to the point where I'm considering throwing in the towel, I run into a player or tune that inspires me.
The "deal breaker" would be when you stop learning/improving.
I stopped playing a very lucrative 14 year patio job because of the nature of the snobs who frequented the place, rather than just be miserable. Then, I took a job at a little buffet place...$8.95, all you can eat. Everyone warned me that I would ruin my reputation, but, I stayed 3 1/2 years and am now going to the owner's 2nd restaurant-a well-known Chinese place.
Music is what you make of it. For me, if I stop playing or working, I have failed and ceased to do something that has been a major part of my life for 80% of my life.
After all, that's the only way I ever got laid (LOL)!
Sorry, folks...priorities (in the past), you know.
Russ