You know what I noticed about Jerry Seinfeld lately? The guy still LOVES the joke. He loves the entire process of writing them, hearing them and performing them. Despite his amazing success and the knowing of the science behind the joke he remains childlike in his quest for funny. Have you ever took a good look at Seinfeld's face when he's hearing a great joke or he's in the process of thinking about some part of the setup-punch line? You can see the kid in him come to the forefront.