You know, I have a love/hate relationship with math.
Right now I'm loving how easy it is to derive and integrate hyperbolic trigonometric functions!
I was fine with derivatives and differentials. The rules were pretty simple, and once you covered each of the variations, you were set. It was actually fun (in a sick way). Integrals were mostly just reversing things, and covering the rules for the constants. (Yes, I know that's a massive oversimplification.)
Then we got to integration by parts. Then nested integrals, and other "next level" stuff, and I started losing it. I managed to limp through my last term of calculus with a 2.5, and got into advanced calculus.
The textbook was "Advanced Calculus - An Introduction to Analysis". I just went
Holy Fucking Shit! The advanced course in something that was already blowing my mind is only the
intro to something else! I passed advanced calculus (the second time) and then switched majors. I'd reached the limit (ha!) of what my mind could handle.