I would end every night reading these ten letters. It made the numbers and the policies very concrete and very specific. And I was reminded that the choices we were making were affecting millions of people. I found that to be very useful.

Long years ago, sometimes it seems many lives ago, I was at Oxford listening to the radio programme Desert Island Discs with my young son Alexander. It was a well-known programme (for all I know it still continues) on which famous people from all walks of life were invited to talk about the eight discs, the one book beside the bible and the complete works of Shakespeare, and the one luxury item they would wish to have with them were they to be marooned on a desert island.

The great singer Um Kulthum (actually named Kawkab Elsharq – a superstar of the East) had a major influence on my appreciation of music. On the first Thursday of each month we listened to Um Kulthum's concert – "waslats" (three songs) – for more than three hours. During all of my study years in Egypt, the music of this unique figure gave me a special happiness, and her voice was often in the background while I was studying mathematics, chemistry… etc. After three decades I still have the same feeling and passion for her music.

We spent some time in our family talking about what's the trade-off we want to make. We ended up talking a lot about design, but also about the values of our family. Did we care most about getting our wash done in an hour versus an hour and a half? Or did we care most about our clothes feeling really soft and lasting longer? Did we care about using a quarter of the water? We spent about two weeks talking about this every night at the dinner table.

You have to be intelligent, and be able to cope with stress. It is a stressful life, both mentally and physically. Those are the qualities to succeed as a surgeon.

I think so. I really do. With your own effort, you can improve yourself, but people find they can’t improve beyond a certain point. I like to play golf, but I know that no matter how much I practice, I will never get above a certain level. I think that’s also true of surgery. Some people are born with the gifts and the mind for surgery, and they may go on to great heights. Others may try and try, only to reach a certain plateau.

The man who inspired me most, I think, was Dr. Alfred Blalock, who was professor of surgery at Johns Hopkins. He was a rather simple man with a burning curiosity. It was through his curiosity that he made many real contributions to medical science. I didn’t think he was an especially brilliant man, I just admired him for his curiosity, and for his perseverance.