François Mitterrand was a student of architecture, he had done a lot of research before he called me. He said, "You did something special at the National Gallery of Art in Washington - you brought the new and the old together." But John Russell Pope finished the West Building in 1941, so when the East Building opened it was only about 40 years old. But the Louvre is 800 years old! A much bigger design challenge.

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.

At home, I have a wife, fortunately, and my children are all grown, and I have many grandchildren. I spend weekends with my grandchildren; I adore them.

Qatar does not have much history, it's a new emirate. So I couldn't draw on the history of the country; its history is really just being a desert. But I thought, the one thing I must learn about for this project is the Islamic faith. So I read about Islam and Islamic architecture, and the more I studied the more I realized where the best Islamic buildings were.

It is not an individual act, architecture. You have to consider your client. Only out of that can you produce great architecture. You cannot work in the abstract

Architecture is the very mirror of life.You only have to cast your eyes on buildings to feel the presence of the past, the spirit of a place; they are the reflection of society.

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.