I had been used to improvising and even in the audition I was feeling free to rearrange Aaron Sorkin words a little bit, as lovely as they were. I didn't find out until after I got the part how furious Aaron was at me for doing that. They said, "He was livid. He did everything in his power not to jump down your throat!" But I came to realise that Aaron was writing in metre and the rhythm of the language is very important.

I would love to be in the position where the role is challenging enough that I need three months to prepare for it and then six months to live the life of character.

Surviving the grind of 18-hour days and getting up at four in the morning to work out for an hour so I'd have the energy to do it again the next day. I did not know I had that discipline. I did not know I had the discipline to learn a seven-page scene in three hours to shoot that day or the next day. I didn't know that I was capable of realizing that potential.

I remember the day Richard Nixon won in 1968. That was a time that seemed certain to bring about long awaited seismic change in America. But events of tragic proportion took us on a turn. Bobby Kennedy and Martin Luther King, Jr. were suddenly dead.

There's a genetic memory that stays on your bones. What you experience when you're young, I think it stays with you.

If you go to the real West Wing in the White House it looks like a boring law office; there's really not a whole lot going on in series. The moulding is frayed, the carpet is a little dirty; it's not exciting.

I was doing a play out in L.A. 20-some-odd years ago called 'Goose and Tomtom' by David Rabe, and somebody saw it and the next thing I know I'm doing the table read of the film version of 'Glengarry Glen Ross' with Al Pacino and Jack Lemmon - one of the great films of our generation.