The sound is tied to Homer Simpson from the long-running animated TV series The Simpsons, which debuted in 1989. His D'oh became one of the show's best-known catchphrases and spread far beyond the series through compilations, reaction videos and meme edits. Online, people use it as a quick audio shorthand for failure, embarrassment or realizing a dumb mistake too late. Its staying power comes from being instantly recognizable, very short, and easy to drop into almost any comedic sequence.