The narrator shares his story in "The Tell-Tale Heart" because he is trying to convince the reader (and himself) that he is not insane. Throughout the story, the narrator repeatedly declares that he is not mad, even though his actions and thoughts suggest otherwise. By recounting the events that led to the murder of the old man and his subsequent madness, the narrator is attempting to justify his actions and prove his sanity. Additionally, the narrator's need to share his story may stem from a desire for validation or absolution for his crime.
