This short line has circulated online as a standalone reaction sound rather than as a clip tied to one famous scene. Its appeal is simple: almost everyone has heard, or said, a version of 'I don't believe you' when a story stops adding up, so listeners recognise the attitude at once. Creators reuse it in memes, reaction videos and short comedy edits because it needs no setup and reads clearly even at low volume. Its very brevity helps it survive, as it can be dropped into a pause without breaking the flow of a joke.