The phrase idk has long been shorthand online for I don't know, and repeating it has become a familiar meme way to dodge a question without sounding rude. Paired with a quick bye bye, it works as a comic exit line in short videos, reaction clips, and group chats, where the speaker gives up trying to explain and leaves instead. Its appeal comes from that relatable feeling of not knowing what to say, and the short, repeatable rhythm makes it easy to drop into edits, stitches, and replies whenever a conversation needs a light, dismissive ending.