I recited Pi to 22,514 decimal points in five hours and nine minutes. I was able to do this because of weeks of study, aided by the unusual synaesthesic way my mind perceives numbers as complex multidimensional coloured and textured shapes.

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

Why learn a number like pi to so many decimal places? The answer I gave then as I do now is that pi is for me an extremely beautiful and utterly unique thing. Like the Mona Lisa or a Mozart symphony, pi is its own reason for loving it.

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.

My algebra was relatively poor. I found it very difficult to use equations that substituted numbers - to which I had a synesthetic and emotional response - for letters, to which I had none. It was because of this that I decided not to continue math at Advanced level, but chose to study history, French and German instead.

I had eventually come to understand that friendship was a delicate, gradual process that mustn’t be rushed or seized upon but allowed and encouraged to take its course over time. I pictured it as a butterfly, simultaneously beautiful and fragile, that once afloat belonged to the air and any attempt to grab at it would only destroy it.

Fischer, the great American chess champion, famously said, 'Chess is life.' I would say, 'Pi is life.'