What is the moment when you realized, "My teacher is an idiot"?

I've told this one before here on the ol' Reddits, but I had a teacher give me 0% on an assignment regarding exotic animals because she thought Tasmanian devils only existed in cartoons, even after being provided with evidence to the contrary. I used an Encyclopedia Britannica multi-media encyclopedia CD as my source, as the internet wasn't quite a thing yet.

This potato-headed 'teacher' was so adamant and angry about the non-existence of Tasmanian devils, plus the embarrassment of being called out by an 11 year old, that she made that class a living hell for me for the remainder of the year. She was, thankfully, disallowed from grading any of my assignments from that point on (though she was still allowed to grade other students).

/r/AskReddit Thread