What do we learn in "Notes" about the previous story?

In “Notes,” the narrator speaks very candidly about his own narrative tricks. Again he calls attention to the fact that the book is fiction. O’Brien points out that it is a constructed narrative, a piece of artwork rather than a piece of “truth.” O’Brien was emotionally involved with the person, Bowker, but emotional truth does not always indicate factual truth. Moreover, in this chapter, O’Brien writes as a cold observer, as a writer, about what “works” and what “doesn’t work” in fiction. He worries that by moving a literary element like a lake he cannot properly mirror the shit field. He does not worry about why Kiowa is dead, as the character of O’Brien does. This literary doubling of character (narrator) and author is kept up throughout the book. One possible influence for this is Argentinian writer Jorge Borges, who also famously wrote about himself in ever-increasing mise-en-abime patterns.