Answer:
Due to the first-person point of view, readers learn the narrator's own analysis and explanation for his behavior.
Explanation:
If a story is told from the character's perspective while using pronouns such as "I" or "me", we can identify the point of view as a first-person one. That sort of narrative is not omniscient, which means readers can only know what the character who is telling the story knows or wants to share. Also, the narrator is not reliable, since he or she is expressing his or her own opinion and knowledge of facts. Readers cannot completely trust what is being told.
In the excerpt of "The Black Cat" given in the question, the narrator is expressing how he felt as a means to justify what he did to the cat. It is his own biased explanation, what he felt, not necessarily what really took place. His feeling as if he was possessed may be his own way to rationalize his violent actions. By reading it, the audience gets an explanation, but a biased one.
