Physics somehow in my memory figures lower than chemistry for some reason. For example, when I went to MGS I'd done A level mathematics and A level chemistry. I hadn't done physics except at O level. So when I went to Manchester Grammar School for example, they'd already done a whole year. I'd never done things like heat and light or whatever it was, I had to catch up. So I did a bit, but I was not particularly good at experiments either, and I remember clearly, you know, the kind of situation would happen in the final examinations at A level you had to do something, bit of experiment. They'd give you some bit of wire for example, and they'd say, ‘Measure the resistivity of the wire and plot the graphs’, and I did all the experiments and only at the end did I read it said cut the bit of wire into 10 centimetres length. So being a mathematician, I just said well re-scale the answer to this. But it shows that I wasn't really cut out to be an experimentalist.

And so, when I came to Cambridge, I discovered that you had to do physics – applied, theoretical physics – and I was very pleased to discover that theoretical physics here meant Maxwell's equations and potential theory. It was really very mathematical, so I quite enjoyed that; but at school you don't get so much of that, you get much more of the wire and the concrete down the hands stuff which I wasn't very good at, and so that put me off. The sort of higher intellectual challenge of physics, which you reach at the higher stage, which is mathematical, you get at university. And then I got moderately interested in it, but at university I chose the pure mathematics options; I did the physics, I quite enjoyed the theoretical physics up to a point, but I didn't… I wasn't at that stage won over by it. But so gradually I acquired more interest in it over many years, but not at an earlier stage; the early stage I was really a pure mathematician and I did the other things because I had to.