I think for many people who have had that level of success, the idea of "just retiring" is not very appealing. They have gotten to where they are because they

I think for many people who have had that level of success, the idea of "just retiring" is not very appealing. They have gotten to where they are because they have a strong drive to accomplish things that doesn't go away. If they just stopped everything and took a vacation, sooner or later they'll probably find themselves bored and want to dive back into a significant project again.