Huh? At what level does it become too abstract to understand? Calculus? Differential equations? Calculus of variation? Vector and matrix operations?
The whole beauty of math is it is color blind, objective not subjective.
Math classes will become increasingly difficult and weed out those who cannot understand the material, it varies from person to person.
“At what level does it become too abstract to understand?”
Well, wrapping your head around quaternions is a bit of a doozy. I know they work, but I don’t think I could quite explain to you why they work...
Well, personally, for me the level was Algebra. Fortunately, our two daughters took after their father in math aptitude.
I got hung up on “Prove that a unique minimax estimator is admissible.” It had something to do with lim inf over a sup over theta. Yeah, that was statistics, but there were similar proofs on the math side.
Lest we forget ... Quaternions!