This short line comes from The Simpsons, the long-running American animated sitcom known for its large cast of Springfield characters, including Lenny Leonard. The phrase plays on Lenny's name and a simple mix-up with a group of kids, which makes it easy to lift out of context and reuse as a reaction. Online, short Simpsons voice clips like this are shared on soundboards and in meme edits because the show's dialogue is widely recognised and its delivery is instantly familiar. Its appeal is that specificity, a tiny moment of correction that still works without the original scene.