I was advised to take the most advanced math available in high school. That was AP Calculus AB. I did OK in that course. But that class teaches you how to pass the AP test. That's it.
Some of the best advice I ever got was to re-take it in college. If I had learned calculus to the extent that you need to to understand an engineering textbook, it'd be an easy A. If not, well, I should be glad for a second opportunity to learn it thoroughly. Turns out I needed to take it again.
Math is the language of logic. It's basically a foreign language for all humans.

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