2012-07-26
Explanation
This comic is labeled "Geek Parenting Perk #7297352: The Lamest Jokes in the World" and shows a parent telling a knock-knock joke to two children, but the dialogue is presented in reverse order. The conversation reads from bottom to top: "Knock knock." / "Who's there?" / "Time reversed owls." / "Time reversed owls who?" / "Of course they do." The joke is that the speech bubbles are arranged so the punchline appears at the top and the setup at the bottom, as if time has been reversed.
The humor works on multiple levels. First, the joke itself is about time reversal -- owls say "who," and if you reverse the sequence of a knock-knock joke, the answer "Of course they do" (confirming that owls say "who") comes before the question. Second, it is a self-referential "geek parent" joke -- the kind of overly clever, groan-inducing wordplay that a science-minded parent would inflict on their children. The absurdly large perk number (#7297352) implies there is a nearly infinite list of such dubious privileges that come with being a nerdy parent.