You can be enormously effective for a period of time, because it's almost like there's an engine in you that needs to keep going, and you have a greater drive than other people - who may be more happy and balanced in life - because you have to keep going out and proving yourself over and over again.

One of the important qualities that I think is often overlooked is just energy. It's vitality, and sort of a life force that some people have and others don't. Probably that is connected to a love of whatever it is that they're doing. Another quality that I think is central is confidence. Again, some people are more blessed with that than others.

Good leadership requires you to surround yourself with people of diverse perspectives who can disagree with you without fear of retaliation.

Excitement about things became a habit, a part of my personality, and the expectation that I should enjoy new experiences often engendered the enjoyment itself.

Politicians generally form alliances and not friendships. Individuals and institutions achieve their ends through continual barter. But deals are not bonds. Indeed, intense emotional involvement with anything - with issues, ideology, a woman, even a family - can be a handicap, not only consuming valuable time, but more importantly, reducing flexibility and the capacity for detached calculation needed to take maximum advantage of continually changing circumstances.

What I learned, more than anything, was that you can't have it all balanced perfectly at any one time. When I was young, it was much more balanced toward work. When I had my children, it was much more balanced toward love and family, and I didn't get a lot of work done. So you can't ask of it to be perfectly balanced at any time, but your hope is, before you die, you've somehow had each of those spheres come to life. That's probably more important than success in any one of those spheres alone.

If you interview five people about the same incident, and you see five different points of view, it makes you know what makes history so complicated. Something doesn't just occur. It's not like a scientific event. It's a human event. So the dimensions of it will be seen differently by different people.