There was a time in my life when I was going in and out of houses that were extraordinarily different - from a working-class terrace in Northampton to the homes of friends who were really very wealthy. It was quite an odd position to be in, I realise looking back, and quite a nice one.

And what he meant was that maths wasn't like life because in life there are no straightforward answers in the end

At teenage parties he was always wandering into the garden, sitting on a bench in the dark . . . staring up at the constellations and pondering all those big questions about the existence of God and the nature of evil and the mystery of death, questions which seemed more important than anything else in the would until a few years passed and some real questions had been dumped into your lap, like how to earn a living, and why people fell in and out of love, and how long you could carry on smoking and then give up without getting lung cancer.

And when the universe has finished exploding all the stars will slow down, like a ball that has been thrown into the air, and they will come to a halt and they will all begin to fall towards the centre of the universe again. And then there will be nothing to stop us seeing all the stars in the world because they will all be moving towards us, gradually faster and faster, and we will know that the world is going to end soon because when we look up into the sky at night there will be no darkness, just the blazing light of billions and billions of stars, all falling.

... why I like timetables, because they make sure I don't get lost in time.

And it's best if you know a good thing is going to happen, like an eclipse or getting a microscope for Christmas. And it's bad if you know a bad thing is going to happen, like having a filling or going to France. But I think it is worst if you don't know whether it is a good thing or a bad thing which is going to happen.

You love someone, you've got to let something go.