A long time ago I took Latin at High School.
For two years we had a very cool teacher, Mr de Leeuw, who was a polyglot. Well, he spoke eleven languages. He was also quite a raconteur and had a good sense of humour.
The following year we had someone else, a woman whose name I forget. She did not seem to have a sense of humour at all. One day she said to me “Freshwater, decline ‘this'”
I said “None of those for me thanks”.
There was a silence. Then “Oh, I see. A joke”.