Diet Coke has become a running joke online because so many people treat it as a daily ritual rather than just a drink, and short clips built around that obsession are easy to reuse in memes, reaction videos and short-form edits. The sound works as a quick shorthand for craving, habit and playful exaggeration, which is why creators drop it into everyday scenes, thirst jokes and relatable food and drink moments. Its appeal is not a single viral moment but the shared recognition behind it, so it keeps appearing whenever a joke needs a familiar soda reference.