This sound comes from Young Sheldon, the television comedy about a child prodigy navigating school and family life far ahead of his age. In the scene, a university professor who has been speaking to Sheldon as a fellow academic finally sees his work through a child's eyes and reacts with blunt disbelief. Clips of the line spread through fan soundboards and reaction videos because it fits school, homework and grading jokes so neatly. It remains popular as a short, instantly understood way to call out something absurd without needing any context from the show.