I don’t think of it as research. I read for interest and enjoyment, and when I cease to enjoy it I stop. I didn’t research quantum mechanics but I was fascinated by the mystery that lies in the foundation of the observable world, of which the most familiar example is the wave/particle duality of light. I thought it was a good metaphor for human personality. The language of espionage lends itself to this duality—think of the double agent.

I notice that if you have the door to your office closed, you get more work done today and tomorrow, and you are more productive than most. But 10 years later somehow you don't know quite know what problems are worth working on; all the hard work you do is sort of tangential in importance. He who works with the door open gets all kinds of interruptions, but he also occasionally gets clues as to what the world is and what might be important.

I’ve had this concern all the time, but I can only hope that if one writes with appreciation and delicacy and respect, then it’s okay. I have to say that I’ve written a hundred times as much as I’ve published, because if there’s any thought of offense or embarrassment, then I will put the thing quietly away.

It’s how we are made as homo sapiens. We are biologically organized to cover distances on foot. That’s what we did for tens of thousands of years until we started to use horses, of course, until the mechanical age. And I would not call it “walking” because it’s not going out for a stroll or going out for a “power walk” or ambling in your city. It’s “traveling on foot.” You are reading the world, learning the essence of the world.

“David, you are going to walk among kings.” This was my mum’s prophecy when I was small. My father is from a royal family in Nigeria, so I interpreted it that way. Remarkably, she was right: I went on to play King Pelasgus, Henry VI, Martin Luther King and Seretse Khama.

Right now. I am a very blessed man.

Being a father teaches you very quickly that you are not the center of your own universe. That’s one of the gifts of having to wipe poop!

God has never let me down. He’s a key factor in guiding my decisions and feeling safe within them. My wife and I suffered three miscarriages, one of them quite late in the pregnancy. Without faith, we would have retreated into our own corners to lick our wounds, but our love increased.