Oleguer Cartero circulates online as a short, context free Spanish audio clip shared on soundboards and in meme edits. Its exact origin is not widely documented, so its popularity comes from use rather than a known scene or broadcast. The pairing of a distinctive Catalan first name with the everyday word for postman gives it a specific, almost storybook quality that Spanish speaking users recognise instantly. It survives because the phrase works anywhere, as a random introduction, a fake announcement, or a joke answer to who is at the door.