Old math teacher would put homewoek assignment on board at start of day.
So I would just solve it during class. Teaching myself from the book.
One day assignment wasn’t on board. So I asked her for it so I could do it during class.
She was confused and asked me how I was going to learn the material if I wasn’t paying attention.
Well it turns out people get really upset when you logically explain how you don’t need them since the book teaches it just fine.
Then I had a professor who had an accent I struggled to understand. Thankfully, she picked a fantastic Linear Algebra textbook. That's when I realized that the textbook is debatably the most important part of a class (at least for math and science).