Grade school, high school, college... whatever.
I'm taking a psychology class to knock out some required credits in school and my class is taught by some elderly woman who was a psychologist for 25+ years or somesuch. The first day, she has us all introduce ourselves and say why we're taking the class, what we plan on doing with our majors, yadda yadda. She has some kind words for everyone.
The second class, we're going over the principles of scientific research and how important empirical evidence is and the risks of letting variables affect your research, etc. The last part of the section is about pseudo-psychology (phrenology, graphology...). She goes into a twenty minute spiel about how psychic powers are real and talking about how psychics are important for solving crimes and stuff.
The third class, we go over the study guide from the section. She wrote the study guide. She passed out the study guide. She has no fucking clue what is on the study guide and continually gives us nonsensical wrong answers. When students stop and say "Wait a second... 'Freud is considered the father of accurate ' makes no sense", she repeats the inaccurate answer she gave a few more times and then skips ahead to some other question. Or else blames it on "probably being a typo".
The fourth class, we go over more study guide fun (on another section). Same deal. Some lady makes the mistake of calling her "Mrs." and she goes on a five minute tear about how it's "Doctor". Then we take a test.
I've had teachers who were obviously bored and uninterested. I've had instructors who were obviously overqualified for the class and was way over our heads (had a "Principles of Econ" instructor who had only ever taught graduate level courses). I've had teachers who were just disorganized or naive or were otherwise fluff. But I think this woman is my first truly incompetant instructor.