I think I was good at easy math, and I refused to follow directions. I saw that arithmetic and early algebra had a lot of generally useful principles and I avoided memorizing and would just "think really hard" and I did well enough. I struggled with factoring polynomials (I think it was), and then really started to struggle in Calculus 2. I wish someone had sat me down and said "look, you're not learning universally applicable tools anymore, you just need to memorize these tricks, know that they only work sometimes in the real world, but they will work on the test, just follow the directions!"
Yeah, basically I crashed and burned there and have been stuck ever since. I was studying at a university where CS was treated effectively as a second math department, which is fine, but not when I had a mental block for integration.
https://xkcd.com/2117/