'Memento Mori' is a short story focused on a man with anterograde amnesia who seeks revenge for his wife's murder, and it has been adapted into the film 'Memento,' which alters some narrative elements while keeping the core premise. The protagonist, Earl, experiences the challenges of memory loss and his attempts at vengeance, illustrated through multiple narrators and symbolically significant elements like a bell that represents his fragmented existence. Both the short story and the film explore themes of memory's fragility and the psychological effects of trauma on their characters.