I passed 8 O-levels in my fifth year, and, with one other boy, transferred to the local grammar school. I thought I'd stand a better chance of getting decent A-levels there, though I suspect that was a not true. No idea now, of course.
I did enjoy my time at the secondary modern, though looking back, I realise I was very snobbish about the school and my fellow pupils. I figured I was going to university, and few of them had any such ambitions. I didn't mix with them socially much, either.