Earlier quoted context omitted.
Math as a field of study might be hard but in my experience math pre grad-school is just memorization as much as any other subject. I studied for my exams by simply doing countless exercises and memorizing every problem pattern to the point where I'm just plugging numbers into a series of formulas, even if I don't fully know why I'm doing so.
This is my experience as well. And unfortunately, many of my teachers feed into this. "Ok kids, today we're going to learn this new formula. You put a number in, do some arithmetic, and you get an answer out. I am not going to bother explaining the importance of this formula, how it came into existence, nor its practical application — likely because even I don't know. But what I do know is it's important because ever…
Short story time: I never could memorize various geometry equations, like surface area or volume of basic shapes. Then one day while bored at my part time job, I found a paper and pencil and decided to use what I'd just learned in calculus to see if I could derive one of those equations, by leaving variables in instead of using concrete numbers.
It totally worked, I reinvented the volume of a sphere equation and ever since that day I've never forgotten it because now every part of the equation has meaning. I know why it is the way it is, and it makes sense.