"A&P" is the story of Sammy's coming of age. Quitting his job to stand up against conventional morality is a defining moment in his life. We think it makes him something of a hero. At the end of the story, he's afraid it will give him a bad reputation in his community and hurt his chances at getting ahead in life. However Sammy's life turns out, he's unlikely to ever forget that Thursday afternoon in the summer of 1961.
The story is also meant to be realistic, giving us a look inside the mind of a typical 19-year-old boy who's girl-watching while he works. And everything that happens in the story feels like it could happen in real life. There's no time travel, talking robots, vampires, or anything like that.