Bill Clinton didn't want it to end. So enamored was he of being president of the United States that, late in his second term, he studied the constitutional amendment that bars a president from serving more than two terms, to see if he could find any loopholes. "I love this job," he said at the time. "I think I'm getting better at it. I'd run again in a heartbeat if I could."

Slideshow: The Post-Presidential Life

Some jobs are harder to leave than others, but few transitions are as dramatic as leaving the presidency. It's a role that can get your face etched on coffee mugs, middle schools and, occasionally, mountainsides. Dwight Eisenhower compared leaving office to death. (Worse than death, argued Richard Nixon.) Jimmy Carter called the prospect of a long retirement "deeply discouraging."

So how do they manage what comes after? How do the men who have sailed on that vast ocean of presidential privilege adjust to the (comparative) shallows of post-presidential life? And what can the rest of us learn from their experience?

One thing presidents discover — much to their surprise sometimes — is that they have one another. Even before being inaugurated, each new president is quietly welcomed by his peers into the Presidents Club, the most exclusive fraternity in the world. Despite vast differences in age and ideology, each president has more in common with fellow holders of the title than he does with almost anyone else. "You understand the weight of the decisions the other guy had to make, and you respect that," George H.W. Bush told us. "We don't talk about it. You don't have to."

That unspoken connection can make for strange bedfellows: Eisenhower acting as freelance adviser for Lyndon Johnson; former rivals Carter and Gerald Ford working on more than two dozen projects together; Clinton calling Nixon late at night to ask him not just about Russia and China but about how to organize his day, when to exercise and when to sleep.

Next: What really happens when the Old Boys meet. »