Steven Wright: I finally got around to reading the dictionary. Turns out the zebra did it. 
[the entire audience, except Homer, laughs] 
Homer Simpson: I don’t get it. 
Lisa Simpson: Dad, the zebra didn’t do it, it’s just a word at the end of the dictionary. 
Homer Simpson: I still don’t get it. 
Lisa Simpson: It’s just a joke. 
Homer Simpson: Oh, I get it! I get jokes! 
[laughs] 

The Tempation of the Krust