Who is Cacciato?

I'm really confused... I know, I know... Book #5 was supposed to be lighter and all, but it is definitely not. Exhibit A is the fact that its been almost a week since I finished my last book, because it has really taken some effort to get into Going After Cacciato, which I'm really only about 20% of the way into right now. Maybe it would be more accurate to say that it has taken some effort to get Going After Cacciato. I thought it would be a nice contrast to The Eden Express, since they both happen at essentially the same time, they're both pretty male-centric, and most of the story happens in the woods. I didn't realize that they both also have pretty heavy themes of distinguishing reality from perception. It is definitely not a book to only read just before bed. Partly because I need more brain power than I typically have by that time of night, and also partly because its not at all good for having pleasant dreams. I really like Tim O'brien and his descriptions of the humanity of the Vietnam War, which makes it significantly easier to get into, and I trust that it'll start to come together as we go along here... But at the moment, I'm confused.