“Anyone who’s taken even one course taught by someone who actually knows the material understands why even good students fail with poor teachers.”
My husband (Physicist) tutored a girl in our church who was a freshman in high school who couldn’t catch on to the math. He showed her how to do the work and arrive at the correct answer; she understood. (The method she was being “taught” was to plug in an answer to a software program on a laptop. It didn’t need to make sense; it just had to be the right answer.)
Bad news is that when she got to school and started to do well she explained it to the teacher. Teacher was shown up (she didn’t understand the math), got mad at the girl, and had her switched to another class.
Has your husband told you joke that ends “Assume a spherical horse”?