Knock knock!

Guy comes into my office this morning and goes, "Knock knock!" So of course I answer with, "Who's there?" But he in return just goes, "Company shredding." I'm not even sure, if "Shredding" is the name of the company that shreds the sensible data we store in boxes or whether he meant to say that he is from the company that comes to collect the sensible data from our box for shredding. He seemed happy and in a good mood, but he wasn't exactly on the ball.

I wrote that to a couple of friends. Two of them wrote back asking what I had expected. Well, something clever or funny. The other day for example I read something in English that I found quite funny and unusual:

Knock knock
Who's there?
Little old lady.
Little old lady who?
I didn't know you could yodel.

I wasn't on the ball myself though. I should have told him that he should think of something to reply for the already hinted Knock knock joke.

Do you know any good Knock knock jokes? Write them in the comments!