The Curious Case of Benjamin Button explained that Brad Pitt plays a man who ages in reverse in David Fincher's 2008 fantasy drama. The movie tells the story of Benjamin's life from the strange circumstances of his birth in 1918 to a little time after his death in 2003. The Curious Case of Benjamin Button is only loosely based on F. Scott Fitzgerald's story, borrowing the central conceit of someone being born an old man and becoming younger over the course of their life but adding a lot to the story as well. In particular, the movie expands upon Benjamin Button having a great love of his life, Daisy (Cate Blanchett), whom he meets when she was a young girl.
https://screenrant.com/curious-case-benjamin-button-ending-death-explained/