I was taking math classes because I was planning to take degree that required math through college algebra.
At my local junior college I tested into algebra 2. I enrolled, and the instructor assigned homework problems that had the answers in the texts, not the ones without the answers. Thank whatever deity is appropriate. I went to class, took good notes, and then at home. trying to work the problems I was totally lost. I'd look at the answers and then could work backwards to figure out how to get at the answer. Next problem, same thing.
The instructor kept on telling the class that if any of us weren't really prepared for algebra 2, we still had time to backtrack. In the second week we had our first exam. At the end of that period, I went up to her and professed my doubts about being in that class. She asked, "How do you think you did on the test?" I told her I was pretty sure I got a B, and she said, that's good enough. And she was right. I wound up with an A in the class, to my intense surprise and delight.
She was about 4 years older than me at that point, and I quickly connected to her. In high school, my math program was UICSM, which stood for the University of Illinois Committee on School Mathematics. I have never, in all these many years since, run into anyone who has any clue about it. Here's the thing. It was a "new math" program. This was 1962. We didn't have regular textbooks, but paperback ones that we wrote in. We proved EVERYTHING. Trust me on this. It's why I remember a lot of specifics from that high school math, and why I could test into 2nd year algebra some 30 years later. All during the algebra 2, and the next semester college algebra, both with the same wonderful teacher, I'd be sitting in class, we'd be covering something or another, and I'd remember what I'd learned decades earlier.
One interesting thing was that in my high school class we'd learned that something was true "if and only if" something else was true. At some point I asked my college teacher about this, and she told me that that was the kind of language normally used in rather advanced classes.
I am very glad I took UICSM math all those years ago. I actually remember various specifics, but more to the point I learned a system of thinking about things that has stayed with me.
Oh, and every so often, just to keep in shape, I re-work the Fahrenheit to Celsius formula.