Digital Logic Dad-Joked
My professor had taught us about these doohickeys called multiplexers, which we sometimes also call "data selectors," in a previous lecture.
At the next lecture we had a review: he would draw a symbol and we would shout out what it represented, and he was hamming it up, acting like a game show host.
He drew a multiplexer on the board and asked the class, "what's this?" "A multiplexer!" some students called out. "Right! Now," says the prof, "what is another word for 'multiplexer'?" "A data selector!" someone answers correctly. But he looks like the student just blew the million-dollar question. "Hmm... 'a data selector'... no, I'm afraid not—that's three words!"
His two young kids have probably learned not to ask him about what he teaches.
