The phrase is everyday Korean expressing that something feels too unlikely to be true, which helps explain why this short clip travels well as a reaction sound online. Its original recording and source are not clearly documented, so it circulates mainly through soundboards, short video edits and chat shares rather than from a confirmed film or show. Korean speech is widely used in global meme edits, and a compact, strongly delivered line like this can be understood from tone alone, keeping it useful for surprise, disbelief and comic timing across different audiences and contexts worldwide.