In Joyce's "Araby," the narrator tells of his epiphany in the final sentence of the work:
Gazing up into the darkness I saw myself as a creature driven and derided by vanity; and my eyes burned with anquish and anger.
The speaker realizes that he has been living under an illusion, that he has been blind (like the street he lives on), that he's been "dark" (like the bazaar is now), that he's been thinking about the so-called relationship he has with Mangan's sister far more than the relationship deserves.
The speaker sees that the famous Araby bazaar is nothing so grand, hears the trivial, silly conversation among the workers, is disappointed in some way in the articles for sale, and realizes that he, too, has been blind and dark and trivial, as well as self-important. In reality, Mangan's sister probably barely even knows he exists. And she doesn't even have a name in the story. The narrator gives up his studies, obsesses, suffers in his waiting, and then realizes how trivial he's been.
An epiphany is a transformation, a growing of self such as the gaining of wisdom. In the short story "Araby" from the Dubliners collection by James Joyce, a young boy starts to grow up as he moves from seeing the world and relationships through the eyes of a child to the more realistic or cynical eyes of an adult. He carries the "goblet" of his idealistic dreams about a young girl he knows through the forest of people and emotions he encounters on his way to a church hall sale to get her a gift. This odyssey takes on an enormity of resolve that is unwarranted - the girl is really not that bothered, and neither is anyone else as he finds out when he gets to the bazaar. In everyone else's eyes it is just another day, just another sale, at the conclusion.