via Harvard Business Review.

The problem is that most people, having attained a position of power, are reluctant to leave it and venture into new territory. Often, having racked up accomplishments and seen them celebrated, they are fired up by the possibility that, with a little more time, they could do more. In some cases, they cling to office because their age suggests they will not go on to scale any greater heights. Yale professor Jeffrey Sonnenfeld described this phenomenon in his decades-old book, The Hero's Farewell. In it Sonnenfeld noted that while some aging CEOs exited gracefully while they still enjoyed wide acclaim, many hung on too long, reluctant to face their own mortality. There was William Paley, the titan of CBS, who challenged his biographer by asking just why he had to die. And there was Armand Hammer, CEO of Occidental Petroleum, who put in place a long-term incentive plan for himself with a ten-year payout horizon — when he was in his 90s. Few executives or political leaders are as wise as UCLA's legendary basketball coach, John Wooden, who retired after winning his tenth championship — quitting while he was on top.

My wife has a phrase, "leave before the party's over," which contains much wisdom about the importance of leaving positions before our charms have faded, and about the discipline required to do so.