I can’t remember anything wildly wrong. Closest I came to that was from a private tutor my parents had to hire to make up for too many days I missed due to health problems one semester. One day when we were covering evolutionary biology she goes, “Well, I don’t believe in this, but I’m obligated to teach it to you.” Doesn’t inspire a lot of confidence, but I appreciate the candor. Also I remember a girl in my class in middle school saying her grandmother believed dinosaur bones were put there by the devil and the teacher had to give an awkward response to that.

There is one common misconception among English teachers that I think everyone has heard at some point, the difference between “effect” and “affect” being different parts of speech.