The problems I encountered were just repeats of problems I solved repeatedly during my career. Experience enables one to develop a solution to a fresh problem from a personal data bank of previous problems and solutions.
Throw in that I had at least two direct reports that could do my job, and I was considering leaving. When my UK-based company decided to transition our division to UK management, it was apparent that it was time to go. It was hard to leave a job I loved, even knowing the timing was right.
After I left, one of my direct reports, ten years younger, got my position. That was satisfying. The thing is, I still have working friends who need to stop. My friends fall into two groups.