Keeping all devices aside 1 hour before sleep, stopping all work chats at Zerodha unless critical after 6pm, and spending time doing what is most relaxing just before sleep (spending time with my son & hobbies) and on weekends has helped me the most with sleep.

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.

What we've done all of these years is very simple, is use the little tool, which is ask three whys in a row. Because the first why you always have a good answer for. The second why, it starts getting difficult. By the third why, you don't really know why you're doing what you're doing.

If I don't do that with the bottles, then I sit down, I could be thinking of something else. If I do always the same things, it means that I am focused and I'm alert to think purely about tennis.

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.

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.