My favorite math joke, imagine a professor speaking: "I explained it in my seminar, but they didn't seem to understand. So, I had to explain it again, and again

My favorite math joke, imagine a professor speaking: "I explained it in my seminar, but they didn't seem to understand. So, I had to explain it again, and again they didn't get it. I ended up explaining it a third time, and by that point I understood it, but they still didn't understand. Many more jokes of varies quality: https://mathoverflow.net/questions/1083/do-good-math-jokes-exist https://mathoverflow.net/questions/1083/do-good-math-jokes-e...