Knock knock

Why oh why did I ever teach my kids about knock-knock jokes? I did it once to make Samantha laugh and they have turned it into a whole new game. The only problem - they don't really get the art of the knock-knock joke. Do you remember the old one from grade school that goes like this:
"knock-knock"
"who's there?"
"banana"
"banana who?"
"knock-knock"
"who's there?"
"banana"
"banana who?"
etc
"knock-knock"
"who's there?"
"orange"
"orange who?"
"orange you glad I didn't say banana?"

So this is the one I told Samantha..and has been retold to Alexandra. But they don't get that the funny part of this is "orange you glad I didn't say banana". So their jokes go something like this:
"knock-knock"
"who's there?"
"candy cane"
"candy cane who?"
"aren't you glad I didn't say plate?"
followed by endless giggles from them. Who knew all you had to do to make a knock-knock joke funny was pick random items you see around the house? And they go on like this FOREVER!

.....but there is nothing sweeter than listening to them laugh, so I'll continue to listen to their jokes and pretend to find it as funny as they do.