M'en fou is a French expression that translates literally as I don't care, and it has become a handy shorthand online for indifference. Because the clip is so brief, it works as a quick reaction sound rather than a piece of dialogue, and creators tend to use it when they want to dismiss something without engaging with it. Its appeal is in its tone: calm, detached, and a little cheeky, rather than angry. That makes it easy to reuse across memes, short videos, and reaction edits where a single unbothered line says more than a long reply.