There will be those that do and dont get the “nitty gritty” of the theory side of the math. Those people sometimes become math majors. Normal people (joking, dont be mad math majors), need more than simply the theory side of the math and actually need to see/perform the application side of things. I never once “understood” the lesson in math class when we go over the equations with variables only. I only truly began to learn the material and be able to use it once we got to the example problems. We would do multiple in class and then I would understand how to literally go through the problem and perform the math that was expected of me on the homework, and subsequently the test. There is tons of stuff i know how to use in math, but by no means understand WHY it came to be, or HOW its works for the realm of mathematics. I wanna know how this math can help me solve real life problems, problems I will face in industry, or even just a cool way to apply math in the real world. Not how it will be used in research to find new types of math we wont be able to apply for 70 years.
It was pretty funny being in calculus in college. I was in a class with mostly engineers who were also taking the exact same weed out courses, and nearly every day after the professor would finish showing us the theory side of the lesson, hands would shoot up and the question of, “What application does this have in real life or engineering? Like, how will I actually use this?” always got asked. So not “loving” the theory is by no means uncommon (we all wished for an application focused version of the class to exist, for people like stem students who are not into the math theory lol), but I still see the value in having it presented so that you can have a more foundational understanding instead simply going through the motions
Completely fair point, that I do not think I have the knowledge to speak on. On the Trigonometry Wikipedia page, he pops up a few times, and many trig identities are known as pythagorean identities. Perhaps its not fully trig, but was used as a basis to help discover trig? Without having the understanding pythagorus gave mathematicians regarding triangles, I would think it would be pretty hard to begin developing deeper math regarding said triangles