The line comes from Dumb and Dumber, the 1994 comedy starring Jim Carrey and Jeff Daniels as two well-meaning but hopeless friends whose plans rarely survive contact with reality. In the film, their misplaced confidence makes even an ordinary moment feel like a grand triumph, which is why the moon line works well out of context. Lifted as a short clip, it has become a handy shorthand on soundboards and in short-form edits for claiming victory, however undeserved, and it endures because the joke needs no explanation: everyone recognises the gap between the boast and the person making it.