“I like knock knock jokes. You ever hear a knock knock joke Conan?”
*pause* Conan stares holding back a laugh
“Once or twice”
“Knock knock”
“*laughs* Whose there?”
“It's the police ma'am. Your son has been hit by a drunk driver. He's dead."
The part in joker where he tells a knock knock joke on live tv where the punchline is "it's the police ma'am, your son is dead" feels exactly like something Norm would do to Conan