I have never liked the word retirement. It doesn't feel like a modern word to me. I've been thinking of this as a transition, but I want to be sensitive about how I use that word, which means something very specific and important to a community of people. Maybe the best word to describe what I'm up to is evolution. I'm here to tell you that I'm evolving away from tennis, toward other things that are important to me.

As a very young singer, I was invited to the opera house in Berlin by the then-director of the opera house, Egon Seefehlner, and I had one opera to my name that I knew. He felt that there was a lot that I could learn there, which was very true, and I was so lucky to be able to have this opportunity. The thing that was happening is that I kept being offered operas that I knew that I wasn’t ready to sing, just from an experience point of view, as well as being 24 years old. So I was always asked to sing things that I thought, “Well no, I really don’t think I should sing that now. I need to sing that maybe in five years, or maybe in 10 years, but not right now. Couldn’t I please sing something else?” And that became a difficulty for me. And after being at the opera house for three years, and singing Elsa and Elisabeth — the Wagner roles that are not sort of the heavy Wagner roles — and then Mozart operas that suited my voice at the time, I was continually invited to sing things that I just felt I shouldn’t. So I took it upon myself to go to speak with the artistic director to say that I thought I should leave the opera house, and come back in some years when my maturity sort of chronologically would have caught up with the invitations that I was being offered. Of course, considering that he’d taken me into the opera house when I knew one role, he wasn’t all that happy. I thought he’d say, “Oh, what a smart girl. Oh yes, absolutely. That’s what we’ll do.” No, no. He was absolutely furious.

I read that at a key fork in the road moment for me where I just sold CD Baby and had a ton of money. I was like, “What to do now?” And I read this book from this filthy rich old man being entirely honest, and I thought I should just learn from his experience. ... So if what I’m doing seems weird, it’s because I took his advice to heart and I’ve quit the game.

You gave a six-year-old boy his Laker dream And I'll always love you for it. But I can't love you obsessively for much longer. This season is all I have left to give. My heart can take the pounding My mind can handle the grind But my body knows it's time to say goodbye.

I had set my mind on winning the 1500-meter gold medal in Helsinki in 1952. ... And, it all came disastrously wrong when I came fourth instead of winning. ... Instead of retiring in order to devote myself to medicine, I decided to go on for another two years while I was still a student, working clinically in London, and I did that.

there was already an area of research, the autonomic nervous system, which was relatively neglected. It was between cardiology and neurology, and these areas in between are often the province of neither specialty, and so can lag behind. And that was the area I chose and this changed the second half of my life, if you like, because I then set up a laboratory.

So the values were career, medicine. Sport was something other, something to be set aside.