The exact origin of this cantbelieve clip is not documented, so it circulates online mainly as a generic reaction sound rather than a quote tied to a known character or show. Short disbelief lines like this spread through meme edits, group chats and short form videos because they are instantly understood without context. Creators reuse it for reveals, fails and surprising news, where a brief spoken reaction is clearer and funnier than text alone, which keeps the sound in regular rotation.