The evening classes were a very interesting experience because I suddenly realised I did want to learn mathematics and physics and so forth and so I paid attention, and I had to get through my exams anyway so I had to pay attention to do that. And it all became very interesting and I would travel back on the tube at night with my friend, who's boss had given me a job.  He eventually finished up as a hairdresser. He obviously wasn't very keen on horology. We would stand outside the railway station and talk till 1 o'clock in the morning about the things that we'd learnt that day, you know, and we'd take an equation and we'd pick it to pieces and turn it upside down and really understand how it all worked. And then by 2 o'clock into bed and up at five in the morning to go up to Croydon. So, you know, they were pretty gruelling days, but very exciting.  I enjoyed them all very much.