There is some fear and uncertainty about setting all this down in words, about the act of writing itself. He does not want to be held responsible. It is not what he meant to do when he wrote the novel. His brother never existed, for him, and yet he was an intangible but constant presence. Death can be averted.
Hope lies in continuing to write, in changing the character of the book.
In living the book. More is to come, in the next volume and volumes. We look forward to it. The differentiation hardly matters. He is resolutely digressive in his approach.