Haslingden Grammar was mine.

We all got lucky and passed our 11 plus on a certain day in the early 60's. All my best mates failed, and I knew no one on my first day.

I soon realised that I was below the rest of my class in social status. The teachers made us feel superior to the thickos who were in the Secondary Modern School, including my mates. Social division right there, age 11.

I still mated out with my original friends and didn't meet my classmates outside of school. Two of the teachers in particular had it in for me. Perhaps they were trying to "better" me in their own way - the school had standards to keep up as being superior to the non-grammar schools, and I was a black sheep, Academically, I was good, very good in certain subjects, but I never fitted in with socially superior ethos of the school. And they really loved beating us if we made any transgressions. I left school with zero qualifications.
When I left school I blossomed at Accy College of Knowledge and ended up at uni, very rare for a working class lad in those days.

If you believe in a two tier education system for young people then I strongly disagree. Eleven is far too young to decide their future based on a single days testing.

You obviously had a better experience than I did at Accy.