The professor had a very very long beard (yes at BYU), mumbled, and decided to teach his own research rather than differential equations. Now, as a physics major, I really, really needed to know differential equations very well, and amongst other issues, I really, really struggled with the topic. I ended up leaving my major because it was clear that although I did really well the first 3/4 of the undergrad classes, there was a mental block that sent me into a depressive spin, for a few years, leaving BYU before I graduated.
Eventually I was able to finish a "degree" from BYU via Independent Study, although it was not as a STEM major. My career is not what I envisioned it to be.
It would be unfair and incorrect to blame having to drop out of BYU on this weird dude who chose to not teach the class assigned to him, but he really didn't help at all. He reminded us a bit of Ted Kazinski the Unabomber because it was roundabout at that time.