I like teaching and the contact with young minds keeps one on one's toes.

My father was trained as a saddler, but in fact as a young man worked in his father's business of rearing and selling cattle, so he grew up in the countryside.

However, I should perhaps add that during the 20 years I have been back in Cambridge, I have been actively involved in the teaching of undergraduates, as well as of course supervising research students.

The philosophy of the school was quite simple - the bright boys specialised in Latin, the not so bright in science and the rest managed with geography or the like.

I like working with different directors; it keeps you on your toes.

Shortly after I was born he emigrated to Durban, where members of my mother's family had settled at the turn of the century, and the rest of the family followed soon thereafter.