Happiness vs. Intelligence

The family visits an animation convention, the Sick, Twisted, and Totally F***ed Up Animation Festival, and when Homer is there, he sees Animotion, an animated device that makes cartoons from human movements, and he likes it so much, he invests the family's life savings in Animotion. However, just after making the investment, the company goes into super-duper bankruptcy. To earn the family's life savings money back, Homer finds a job at a medical testing center. During one experiment, the doctors find what appears to be a crayon lodged in Homer's brain, which may explain why Homer is such an idiot. Homer thinks he had a crayon in his brain because he shoved an entire box of crayons up his nose as a child, but sneezed all of them out except for one. After the crayon removal, Homer's IQ goes up to 105 points, which allows him to form a bond with Lisa (not to mention he accidentally proves that God doesn't exist while trying to create a flat tax), but when the nuclear plant is exposed for having a strong record of safety violations, the plant is forced to close down and lay off all employees. Homer's friends reject him rapidly, and Homer is even burned in effigy at Moe's Tavern. Lisa tries to sum up that as you get smarter, happiness goes down. It's up to Homer to get a crayon back in his brain, with the aid of Moe—who says he is an unlicensed surgeon—and become his usual stupid self again. Before the surgery, Homer writes Lisa a letter stating that he now understands what it is like to be smart like Lisa. Instead of being mad at her father, the episode ends with Lisa embracing Homer.