idk if he mentioned, but if you shown promise, you would've been moved to a second tier school, which were prep for top 5-7 universities, school exit exam there being harder than entry, and people in uni knowing those in those schools.. well. to end up in tops one only had to study hard.

on hardcore.. well, idk, we went through intergrals and simple diff equations, and special relativity theory in 10-11th grades. (14-15 yro). It was not that hard.