I truly believe I have a refined sense of humor, but there is just something about knock-knock jokes that crack me up. I giggle like an idiot everytime. Try these on:
I knew you were a nut!
Why so excited?
General Lee who?
General Lee (generally) I don't tell knock-knock jokes.
Oswald (I swallowed) my gum.
Ha ha, tee hee and all that rot.