Knock-knock jokes

[Carol the Dabbler]

I honestly can't think of a single one, and it's driving me nuts.  Anybody know some good ones?  Some bad ones?

[besleybean]

Only the classic:

Knock Knock

Who's there?

Doctor

Doctor Who?

That's right.

[Carol the Dabbler]

Wow, I actually never heard that one!

OK, I'm sufficiently awake this morning that I had made one up (before I read yours, oddly enough).  It's got the more classic format:

Knock-knock

Who's there?

Sara.

Sara who?

Sara doctor in the house?

 

[Caya]

Knock Knock
Who's there?
Dejav.
Dejav who?
Knock Knock

[Carol the Dabbler]

Took me a minute or two!

Spoiler

"Dejav who" sounds more or less like "deja vu"

 

[Arcadia]

Knock knock.

Who’s there?

A little old lady.

A little old lady who?

Wow, I didn’t know you could yodel.