S2E19: Lisa's Substitute

In "The Simpsons" Season 2, Episode 19, titled "Lisa's Substitute," the episode wraps up with a bittersweet conclusion. Lisa is heartbroken when her beloved substitute teacher, Mr. Bergstrom, leaves town. Before departing, he gives Lisa a note that simply reads, "You are Lisa Simpson," to remind her of her unique qualities and potential. Meanwhile, back at the Simpson household, Bart is running for class president against Martin Prince. Despite Bart's charismatic campaign and the support of his classmates, Martin wins the election because Bart's supporters are too lazy to vote. Bart learns a lesson in civic responsibility the hard way. The episode closes with Lisa turning to her father, Homer, for comfort about Mr. Bergstrom's departure. Despite his usual cluelessness, Homer manages to reassure Lisa by expressing his love and pride in her. It's one of those rare moments where Homer steps up as a dad, proving he's not completely hopeless when it comes to parenting.