I thought about this for a while and I said: What’s the youngest anyone has ever gone to Oxford? Sibylla said she didn’t know, in the Middle Ages it was more like a boarding school & she thought a lot of boys would be sent there at 12 or so. She thought a girl had gone to read mathematics at the age of 10 a few years ago.

I said: 10!

She said: I think she’d been taught by her father, who was a mathematician.

If I had had a mathematician for a father I could probably have beaten the record.