Programming is similar to a game of golf. The point is not getting the ball in the hole but how many strokes it takes.

The only way for errors to occur in a program is by being put there by the author. No other mechanisms are known. Programs can't acquire bugs by sitting around with other buggy programs. Right practice aims at preventing insertion of errors and, failing that, removing them before testing or any other running of the program.

I like solitary pursuits, such as reading or pottering about in the garden.

I have a lot of mirrors around my house, not because I like to look at myself, but because I like the light and perspective they bring to a room.

There's such an energy bounding around New York, I can't help but get swept along in it.

Do I think I'm under-educated? Academically, absolutely. I never took any exams, no O- or A-levels.

Roses are my favourite flower, and my mum always grew a lot of them.