Bah humbug was made famous by Ebenezer Scrooge in Charles Dickens' 1843 novella A Christmas Carol, where the miser uses it to dismiss Christmas as a fraud. The phrase became a lasting shorthand for festive grumpiness in countless stage, film and television adaptations. This crowd version flips the line back at Scrooge himself, which is why it works as a collective boo rather than a lone complaint. Online, creators reuse it every December for memes and edits about people who refuse to join in with the season.