I wanted to become a research mathematician because I loved mathematics. Very soon I realized that mathematics is a proselytizing cult, and since my older colleagues taught me and helped me, I had to help younger aspiring mathematicians. From my first year at university I was involved in various extension activities in mathematics for schoolchildren, including running mathematics competitions and a mathematical school by correspondence. Gradually I became a professor of mathematics and learnt to give lectures to 400 students in the audience.