The line comes from Filthy Frank, the deliberately outrageous YouTube character played by George Miller on his TVFilthyFrank channel during the 2010s. Known for surreal sketches, crude humour and deadpan reactions, Frank built a large online following before Miller retired the character to focus on music as Joji. Short spoken moments like this one were later clipped, shared on soundboards and reused in memes because they are instantly recognisable to fans and easy to drop into unrelated videos. Its dry, understated agreement is what keeps it circulating as a reaction sound.