The Saitama 'OK' meme originated from a specific panel in the One Punch Man manga and later the anime during the Boros Saga. After the alien overlord Boros delivers a lengthy, dramatic monologue about his immense power and the prophecy that led him to Earth, Saitama responds with a simple, deadpan 'OK.' This moment perfectly encapsulates Saitama's character: a hero so powerful that world-ending threats have become mundane and boring. The meme is used across the internet to signal a total lack of interest, unimpressed reactions to complex arguments, or a casual, stone-faced acceptance of chaotic situations.