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.

One particular aspect of Siddhartha’s revelation of the outside world has always struck me. Quite possibly he lived his first thirty years without any knowledge of number. How must he have felt, then, to see crowds of people mingling in the streets? Before that day he would not have believed that so many people existed in all the world. And what wonder it must have been to discover flocks of birds, and piles of stones, leaves on trees and blades of grass! To suddenly realise that, his whole life long, he had been kept at arm’s length from multiplicity.

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 remember as a young child, during one of my frequent trips to the local library, spending hours looking at book after book trying in vain to find one that had my name on it. Because there were so many books in the library, with so many different names on them, I’d assumed that one of them — somewhere — had to be mine. I didn’t understand at the time that a person’s name appears on a book because he or she wrote it. Now that I’m twenty-six I know better. If I were ever going to find my book one day, I was going to have to write it.

Often autism is portrayed in the media as a very negative condition, as something that prevents somebody from communicating or from socializing or from being able to have any kind of normal, happy life.

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.

There are estimated to be fewer that 50 prodigious savants worldwide. If we were brought together, it would be disappointing in the sense of us having different abilities. One thing that would make me feel united with them would be the sense of us having grown up in isolation.