This is absolutely not true. You don't have to be some brain genius to learn advanced topics. A lot of it is just studying something you find interesting and engaging. The idea that you have to be some kind of out of normal genius to appreciate art and literature, or study history, isn't true. Most of the hard part of college is the high stakes score high or fail nature of education. The goal isn't to teach, the goal is to grade people like cattle so porky knows how reliably they'll produce profit. Without the profit motive, in a society where the goal of education is to produce education people because that's a good in and of itself, it doesn't matter if someone whizzes through school or takes a decade to get their undergraduate. If education isn't artificially made scarce and hoarded then taking years to get a basic degree is fine. Puttering from discipline to discipline looking for something you jive with is fine.