The pull up warning comes from the ground proximity warning system used in commercial cockpits, including the Boeing 717, where it alerts pilots to climb away from rising terrain. Aviation enthusiasts and flight simulator players have long shared cockpit audio online, and the stark, commanding sound has since moved into memes and reaction edits. Its appeal is simple: almost everyone instantly understands the danger signal, even without knowing aviation, so it can turn a risky moment into an immediately readable joke.