I think with Lyndon Johnson, the most important thing I learned was that he never had the sense of security that comes from inside. It always depended on other people making him feel good about himself, which meant that he was always beholden, continually needing to succeed. He could never stop. There was such a restlessness in him.

When I do research, I have done - 90 percent of my time is the research, the other ten percent is the writing. So I don't have to face a blank piece of paper. I can look at this as a quote that I have from somewhere.

As a historian, what I trust is my ability to take a mass of information and tell a story shaped around it.

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.

They all start competing against Lincoln as the greatest president. And the [library] building becomes the symbol, the memorial to that dream.

The White House is such an extraordinary, simple, beautiful place. It's an extraordinary piece of our history, because it is the one thing that binds our country together. We don't have a king obviously, but we have this president, and the fact that almost all of them have lived in the same place, and so much history took place in those rooms. You can't help but feel awe-inspired by being there.

The past is not simply the past, but a prism through which the subject filters his own changing self-image.