And maintain the mystique. Carson could never understand why so many in the public eye stayed well past their prime. He wanted to be remembered at his best, and consequently though he could have extended his time on television many more years, he went out in his prime. Unlike so many celebrities and wannabes that do anything (even degrade themselves) to stay in the public eye, Carson actually avoided the press at almost any cost.
When I started working with him, I was surprised to learn that he never even utilized a publicist. He understood that his reclusive nature made him more interesting to the public, and it also allowed him to maintain his privacy.