Our interaction with our friends, for instance, is in large part an interaction with representations in our own head of the people before us. That's why a friend can surprise or disappoint us.

The mathematics is the odd one, odd because I'm not sure how to measure its effect. It is so fundamental to my outlook on everything and yet I'm not even sure how. It must be because in my formative years it was everything to me, the single place of beauty in my life, and of breathtaking beauty at that. I still believe that pure mathematics is the most creative thing that humanity does, though I am no longer a part of it.

My own disposition is to trust the reader. Of course, there's a line between trusting the reader and expecting her to read your mind. That's where a friend or an editor comes in. A great editor will tell you straight when you've drifted into the latter territory.

I had a tough childhood, yes. I was born in rural Bangladesh to parents who had had no education beyond high school. We moved to the UK where I grew up in poverty, in some of the worst conditions in a developed economy, before moving to the projects - heaven - and I went to unremarkable schools before going to university. My father was a bus conductor first and then a waiter, and my mother a seamstress.

There have been studies concluding that most people mostly know people only within their own social class - although such a conclusion would hardly surprise anyone. I think there's evidence to suggest that it's even narrower - the great majority of friends of Ivy Leaguers, for instance, are Ivy Leaguers. This narrows the pool of people who can write fiction cutting across class boundaries that's informed by their own personal experience.

I'm interested in how a person forms her beliefs, how that happens. Beliefs of all kinds make up the animating force in each of us. Without them we would be paralyzed, lifeless - the glove without the hand.

Experience belongs to the actor, but the story belongs to the teller. We write so we will never forget.