"There is substantial evidence to suggest that education influences intelligence.[3]" (From Wikipedia)
[3] Baltes, P., & Reinert, G. (1969). Cohort effects in cognitive development in children as revealed by cross sectional sequences. Developmental Psychology, 1, 169-177.
I am saying that school is terrible at teaching. If the goal of schooling is that students learn then the school system I was in was a total failure.
The moment I entered university I learned much more and much faster.
Is it not possible that schooling prepared you for this and enabled you to learn much more and faster?
Why couldn't the school have prepared me for that when I was 16? Why does preparation take precisely 12 years and only then I can really learn anything.
Surely you had peers at school that found mathematics to be challenging, or even struggled?
>Or, what do you think would be valuable then to do (purposely not saying learn) during those twelve years?
I think that this is different between children.
Actually I think it could be extremely valuable to learn, but then the child's activities should actually focus on learning effectively. And sitting in a classroom with children not that interested in learning and a teacher trying to find some middle ground is not helping that.
Personally I believe that with a good school system I would have been perfectly fine doing university courses at 16 and a good school system would have encouraged me to accomplish exactly that.