Season 6, Episode 15: Homie the Clown
When Homer sees a billboard advertising a clown college run by Krusty the Clown, he initially thinks it’s a stupid idea. But then he can’t stop thinking about it and the idea of going to clown college quickly becomes an obsession, much like how Roy Neary (played by Richard Dreyfuss) in Close Encounters of the Third Kind became obsessed with sculpting the Devil’s Tower after his UFO encounter. Just like Roy, Homer channels his obsession using mashed potatoes as a medium and sculpts a circus tent during a family dinner.
Shortly afterward, Homer can’t take the tension anymore.