Short spoken reactions like this became staples of meme editing because they do the work of a facial expression in audio form. The phrase itself is everyday polite language, which is why the contrast feels funny when it is dropped into debates, gaming clips, and reaction videos at the worst possible moment. Creators reuse it as a universal interjection for disbelief, correction, and calling out nonsense, and its very short length makes it easy to layer over other audio without taking over the scene or needing any setup.