Knock, knock

Every family with children reaches this stage at some point.

Jokes.

Waiter, what's this fly doing in my soup?
Learning to swim, sir.

Jokes, riddles, knock-knock books.

They have found where the library files them and they check them out in stacks. Deux is the prime proponent, but the others participate. They keep them in cars and read them off to each other as we drive, reciting them like a litany of humor:

Why did the elephant paint its toenails red?
So it could hide in the cherry tree.

 The twins are technically too young for this stage, but they participate in it just as eagerly as the big kids. Whether they actually get the jokes or not is impossible to tell. They have them all memorized, anyway.

Six copycats were in a car and one got out. How many were left in the car?
None, they were copycats!

I remember when my younger siblings found the Bennet Cerf Book of Riddles and read and repeated them as if they were a new discovery of mankind. And in my adolescent superiority I rolled my eyes. Those old things. I knew them all when I was eight.

Doctor, doctor, when will my measles get better?
I don't know, I don't like to make rash predictions.

Ah, but they are new. The universe is reborn 490,000 times every day. And somewhere, every day, a child picks up a joke book for the first time and "gets" their first pun.

 What time is it when you go to the dentist?
Two thirty!