I thought this was taught in high school. Curriculums differ drastically between countries, don't they?

We were on quarters, so we had calc 1-4. Makes sense that Calc 2 was rough if you were on semesters.

I found linear algebra super hard until I learned it a second and then third time, from different angles. I found it harder to understand when it was taught in a pure maths context, but coming at it from the applied side made me go "oh, so that's why that's like that"

I made it through. My degree is actually in math. 15 years ago, I used to know what an abelian group is!