When I achieved the European record for reciting pi in 2004, this captured the imagination of Professor Simon Baron-Cohen in Cambridge and he finally diagnosed me with Asperger's that year.

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.

We know next to nothing with any certainty about Pythagoras, except that he was not really called Pythagoras. The name by which he is known to us was probably a nickname bestowed by his followers. According to one source, it meant ‘He who spoke truth like an oracle’. Rather than entrust his mathematical and philosophical ideas to paper, Pythagoras is said to have expounded them before large crowds. The world’s most famous mathematician was also its first rhetorician.

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 love music. I have a fondness for Chopin, and I very much like his 'Raindrop Prelude.'

37 is a lumpy number, a bit like porridge. Six is very small and dark and cold, and whenever I was little trying to understand what sadness is I would imagine myself inside a number six and having that experience of cold and darkness. Similarly, number four is a shy number.

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.