As a TA, I've seen adults try to pass initial college calculus many times (and failing - you were allowed to try several times) with enormous effort. It's not a

As a TA, I've seen adults try to pass initial college calculus many times (and failing - you were allowed to try several times) with enormous effort. It's not a small multiplier And this was still people selected from the small subset of the population choosing an engineering major. Human are much, much more different than you seem to think