The guy who taught me system dynamics couldn't answer questions that the class asked. We think he memorized the material before every class, should anything go wrong he would say something like "I'll look into it later" or sit there and think about it for a while then move on to something else.
The guy I have now for our senior projects wants our reports written EXACTLY his way, and his way only. When we describe something, he can never understand it and wants it rewritten. He even described how someone's project exactly works, but said he couldn't understand it in the report. A few times he gave us a lecture about how we don't explain enough, BEFORE he read anything. I had to stop him and say "its in there, just read it!!!" Talk about frustrating! The whole time you're sitting across the table dodging the spit shooting out of his mouth. He also refuses to believe he is hearing is going south. He showed us a video with the volume at max and someone from another class closed our door!

Some of these professors just don’t think, they assume we don’t know anything (or assume we know everything), go off on their tangents, and wind up not teaching anything.
Rant off.