You are referring, of course, to those high achievers like Robert L. "Hoot" Gibson, the former Navy pilot who flew 5 space shuttle missions and was chief of the astronaut office for NASA.

Upon retiring from NASA, he flew for Southwest until he turned 60. And he loved it.

Perhaps there was a bit too much of a generalization in your statement. Sometimes, high achievers get to the point in their lives where they want to simplify a bit -- flying airplanes, getting paid to do it, and then walking off the jetway at the end of the day.