The melody comes from the 1997 film Titanic, where its sweeping romantic theme became one of the most recognisable pieces of film music in the world. Online, that familiarity made it perfect for parody, and sad or slowed versions began appearing in meme edits, reaction videos and short-form clips whenever creators wanted an instant feeling of tragedy. Because almost everyone knows the tune, it needs no explanation, which is why it still works as shorthand for a dramatic ending, a lost cause or a joke taken far too seriously.