"After an amazing first day of a school rotation, I said to the professor basically, “Thanks! This has been a really interesting day!”. The creep thought I was being sarcastic and over the next two weeks tried to wash me out of grad school in the last day of the rotation.
Other teachers told me he was going through a bad divorce and hated everyone, and confronted him in my defense. To this day if anything comes up regarding that topic my blood pressure spikes."