They can’t help it, they just are. Actually, obnoxious isn’t the right word…I think abrasive fits better. Some people are naturally abrasive. An example would be a person who takes pages upon pages of notes in a blow off class and then condescends to you about it. Arggghh. Waste your own time.

EDIT: Also, people who speak about irrelevent subjects in front of the class. Especially when their power point presentation is immaculately ordered and footnoted. Do you honest have nothing better to do? Get a dog.