I had similar questions regarding middle/high school literature studies. So many, so many ideas were out of reach from my soul when I was 15 (say the social contract by Rousseau). But maybe that was just emotional/existential immaturity on my part. Maybe some pupils, arguably a few, really had the maturity to connect with these themes. Maybe also, previous generations were more mature early on. I believe that in mathematics, in the 70s, it was expected to learn abstract algebra in high school, it college.