I've been active all my life. In 1990 I retired from my firm, I.M. Pei & Partners, and for two years I didn't do much. Then I started to get kind of antsy, so I decided, I'm going to do some more work. And I chose to do work outside the U.S. because I've spent 45 years here and I wanted to learn more about what's happening in the rest of the world.

Design is something you have to put your hand to.

Many of the projects I'm most proud of are tall buildings, especially the housing projects. In New York I have two: one in Kips Bay and one at New York University. At that time, those projects were most challenging.

At the beginning, I thought the best Islamic work was in Spain - the mosque in Cordoba, the Alhambra in Granada. But as I learned more, my ideas shifted. I traveled to Egypt, and to the Middle East many times.I found the most wonderful examples of Islamic work in Cairo, it turns out. I'd visited mosques there before, but I didn't see them with the same eye as I did this time. They truly said something to me about Islamic architecture.

I know something about the civilization of China, with my background, obviously, and I think I know something about American history. But that's about all. And I've traveled all over the world, and for a long time I didn't know very much about it, really.

I cannot work and listen to Wagner at the same time, nor Mahler, nor Beethoven's late quartets. I enjoy listening to Chopin's piano music when I work.

Luxembourg was and still is today a crossroads, the place where Germany meets the rest of Europe. The country lost part of its territory to Belgium in the 1800s, and during World Wars I and II the German military overran it. Very few people have visited Luxembourg - when I went there and looked at it, I said, my God, it's built on a rock. And within the rock they had a castle, and within the city there's a network of tunnels so the residents could move around and defend themselves. That was of great interest to me.