Who's the "I" in Infinite Jest?

David Foster Wallace's use of endnotes has my opinion split.

Using endnotes is a great way to build up the peripheral details of a fictional world. This fact goes double for endnotes about something like a character's filmography (complete with archival holes and sticky, uncertain parts).

At the same time, though endnotes work as essential blocks of a world's apocrypha using them for such a purpose is kind of lazy. At the very least, they could be overused. Yet, for the most part, Wallace avoids this problem. Maybe it's the variation in their length, from single sentences to whole scenes, that makes their presence seem almost ridiculous. Though, that raises a very interesting question about the book.

Hal is more or less the main character. But there's been a short section of the book where the central figure wasn't Hal or any other character introduced as yet. In this section (running from pages 61 to 63) the main figure is simply "I." Of whom is this first person perspective? Hal's? The ill Troeltsch? Wallace himself?

Whomever the I actually identifies, must be the one writing (or providing) the endnotes, since they're not written with any objectivity of tone (like those Michael Creighton used). So far, each endnote reads like the book's main narrative, though they have been quite a bit more focused and use far fewer long and lumbering sentences.

I've yet to crack page 100, and yet Infinite Jest just keeps piling on the mysteries. I may be a while in getting back to Hyrule Historia.