My parents were both educated in top public schools. In a fit of egalitarian guilt they sent us all to big- standard comprehensives in a working class area. The smallest class I was in was my A level History class of 15 pupils. Mostly I was in class groups of 35 to 40
But we also did:
a LOT of reading at home. We had books - both bought for us and weekly library trips, plus I had free access to my parents’ extensive book shelves (my father’s study was 3 walls of books). We were read to every night until I was about 12- that was when my youngest sibling was 8.
no television until after supper (which was at around 7pm)
A lot of extra curricular activities and not many of them sports (unless you count Pony Club). Ballet, music, singing, Guides and Brownies, riding lessons, and sailing lessons.
we did summer schools in things like painting, sculpture, music, theatre appreciation as well as doing youth theatre
we really were not encouraged to just sit around at home after school and on the weekend. We were expected to do things constructively. As a result, I’m reasonably proficient at a wide range of activities and skills.
My siblings and I are all very successful in a range of quite unusual careers and professions.
I think the thing that was most difficult was the bullying we came in for because of class differences. Other parents were very suspicious of children who read books and enjoyed school, and egged on their children to tease and taunt us.