Political Science professor A. James Gregor hates a lot of things. He hates Marxists and bellybuttons, Birkenstocks, and undergraduates. He despises callous language, smiling, and public displays of affection. Most importantly though? He hates being disrupted.

So if you’ve got to potty, make sure you do it well before of class. If you’re running even a minute late, it’s better to just not attend lecture than risk being ostracized in front of a lecture hall of 200. And if your cell phone goes off? You might as well just drop the class right then and there.

Watch the video above to witness a regular exchange between Gregor and a poor girl who came into the room in the middle of lecture to retrieve some stuff she had left behind. (Keep in mind that this was the first (and the kindest) of three shit fits Old Man Gregor threw during this hour and a half lecture.)