South Park is the long-running American animated television series behind this short reaction line, and clips like this one have circulated for years on soundboards and in short-form video edits. The phrase works because it is instantly recognisable as sceptical without being aggressive, so creators reuse it whenever a statement needs a quick, knowing challenge. Its brevity also helps: at under two seconds, it can be dropped into a pause, a caption or a reply without slowing a joke down, which is why it remains a handy reaction sound.