I gained a humility that I needed in order to balance my audacity. I wanted to find the smartest people who would disagree with me to try to understand their perspective or to have them stress test my perspective. I wanted to make an idea meritocracy. In other words, not an autocracy in which I would lead and others would follow and not a democracy in which everybody's points of view were equally valued, but I wanted to have an idea meritocracy in which the best ideas would win out.

It was hard at first. I craved the soft, chewy, comforting feel of bread. I craved crunchy pizza dough, sweet rolls, and all the foods that I learned contained wheat—things I had never suspected. For the first 10 days or so, I craved these foods, but I focused each day on staying disciplined; and, fortunately, my family and friends—even though they thought I was crazy—supported me in my quest. But as the days rolled along, I began to feel different. I felt lighter, more energetic. The nighttime stuffiness I had lived with for 15 years suddenly disappeared. By the end of the first week, I no longer wanted rolls and cookies and breads; it was as if a lifelong craving had miraculously abated. Every day I woke up feeling as though I'd had the best night's sleep of my life. I was beginning to believe.

Every year I get more of an understanding of what I need to be happy. If I haven’t slept enough, or if I haven’t exercised, I’m more likely to be in a bad mood. My silly brain will think it’s because I haven’t written a good joke that day, but actually I’m just tired or I need a poo.

One thing that I went through and I was able to understand is: It's OK to not be OK. Right? Like nobody's perfect.

I am happy to sit in silence with my wife and I think that is a good sign – we are just happy being in each other’s company.

Professionally, when I lost my first Wimbledon final. I am also disappointed I didn’t learn Spanish when I lived there.

Driving home on my own, thinking about the last 18 months, which have been really difficult, and getting back to playing tennis again without any pain in my hip. It was happy crying.