At 67 the thought has crossed my mind.
I think when I get to the point of not being able to do my own maintenance it will be time to give it up.
Right now I go up on the roof without a care in the world, I jack up the trailer, move lumber around underneath it without a thought, changed out the black tank valve myself not long ago, think nothing of washing & waxing myself using A frames & boards to reach the high parts & generally being self sufficient fixing anything going wrong no matter what or where it is.
When the physical ability to do all that stuff is gone it will be time to cash in & enjoy the memories.