Teaching words to children is a delight. And a challenge. You do your best to explain what words mean, when they are appropriate to use, and when they are not. Which words are for family ears only. Which words are slang-ish, and when we can and can't use those words. And on and on and on.
Then you tell a little joke like this one. And you realize that, yeah, when it comes to teaching language, you're doing pretty good.
Me: "What kind of bee makes milk?"
Jack: "A cow bee."
"Good guess, but nope. Wanna know?"
"A boo bee!"
[laughter commences, followed by a broad, silent pause]
Jack: "You mean a breast."