Why Portrait of the Artist is unconventional

Read the third section of James Joyce's "Portrait of the Artist as a Young Man" and, as with first two sections, I'm amazed at how little I recall about these, even though this is probably the 3rd time I've read the book - not sure why that is. Possibly because the Portrait itself is not a highly dramatic novel, that is, it's not driven by plot or by conflict in the usual sense: character faced with problem he must confront and solve, narrator goes on a journey, stranger comes to town - none of the usual narrative tropes. It is, as the title proposes, a Portrait, and in that sense rather static - the movement of the narrative, the arc of the story, being the development of the sensibility of the artist/writer, Joyce of course but here called Stephen Dedalus (or Stephen Hero in an earlier draft) - which we see both as the narrator matures and as the style of the novel itself evolves and becomes more unconventional and experimental. In the early chapters, there's nothing that inevitably suggests Stephen is on a path that will lead him to exile and to stature as one of the world's great novelists - seems like an ordinary, intelligent, schoolboy, with the exception that he is extremely observant and attendant to sense details. Third section involves an episode in which Stephen is unfairly caned by Brother Dolan, a sadistic teacher in Clongowes school, and at encouragement of his friends Stephen reports the incident to the Rector and is treated kindly - and becomes momentarily a hero. This section actually a bit more conventional than earlier, an isolated piece, not amazing for its story but very notable for the Stephen/Joyce's skill at evocation - the sound of balls hitting cricket bats like water dripping on slate, and many other examples.