Memes on Current Events on Instagram: "The knock-knock joke is a classic form of call-and-response humor that traces its roots back to the early 20th century. Its structure—where one person initiates with “Knock, knock” and the other responds with “Who’s there?”—creates a playful rhythm that builds anticipation before delivering a pun-based punchline. Scholars link its development to older joke styles and wordplay traditions, but it gained massive popularity in the 1930s when it became a widespr