BRITAIN: Looking Back at No. 10

I have repeatedly been asked what are the main essentials of a successful Prime Minister. Over and above communication and vigilance, there are two factors. They are sleep, and a sense of history. A Prime Minister who can't sleep is no good. Without a sense of history, he would be blind. If you have ever been dead by lunchtime and even worse by nightfall—well, you know others have been through it before you and you can get a sense of perspective.

—Sir Harold Wilson,

The Governance of Britain

Two days after his surprise departure from No....