2014-02-17
Explanation
The Joke
A man on a date is confessing that he has done terrible things in his past. He then tries to absolve himself by arguing that since the human body replaces its molecules over time, and those "shame molecules" have now dispersed across the globe and into other people's bodies, the woman should technically be ashamed of herself too, from a chemical standpoint. She declares this the worst first-date conversation she has ever heard, and he retorts that she will be "partly at fault for it soon" -- implying that his shame molecules will eventually end up in her body as well.
The Humor
The humor lies in the absurd misapplication of a genuine scientific fact. It is true that the molecules in our bodies are constantly being replaced and recycled through the environment. However, the man weaponizes this fact to try to deflect personal responsibility for his past actions in the most inappropriate context possible -- a first date. The final punchline doubles down on the absurdity: rather than accepting that his argument has failed, he uses the same logic to suggest she will literally share responsibility for the conversation she is currently hating. The comic satirizes people who use pseudointellectual reasoning to avoid accountability.