With no clear original clip tied to this short phrase, besides um has spread mainly as a reusable reaction sound on soundboards and in short-form video, where its appeal comes from how ordinary it feels. The filler words themselves are common in everyday speech, which makes the clip instantly recognisable even without a famous source. Creators reuse it to signal hesitation, second thoughts, or a joke that stalls before the punchline, and its brevity makes it easy to slot into edits without disrupting the flow of a video.