When I multiply numbers together, I see two shapes. The image starts to change and evolve, and a third shape emerges. That's the answer. It's mental imagery. It's like maths without having to think.

Like works of literature, mathematical ideas help expand our circle of empathy, liberating us from the tyranny of a single, parochial point of view. Numbers, properly considered, make us better people.

I certainly have routines in my day-to-day life that are important to me and still give me feelings of security and control, but the capacity to break out of them every so often as I travel has given me a second wind.

I would play with numbers in a way that other kids would play with their friends.

When I was a child, my behavior was far from being what most people would label 'intelligent.' It was often limited, repetitive and anti-social. I could not do many of the things that most people take for granted, such as looking someone in the eye or deciphering a person's body language, and only acquired these skills with much effort over time.

I consider social skills a bit like learning a language. I've been practising it for so long over so many years I've almost lost my accent.

I did have a very restricted, regimented life. There was a kind of happiness there, a contentment, but it was a small happiness within very clear and delineated borders.