One of the most enduring stories I read as a youngster, which has remained etched in my mind, is Rip Van Winkle by Washington Irving. I still remember the vivid picture it painted in my imagination of a man who, tired of the world, wanders into the mountains, drinks a mysterious potion, and falls asleep for twenty years. When he finally wakes up, he finds that everything has changed. The American Revolution has taken place. The world has moved on without him.