Matt only appears twice in the book, and never evolves beyond his obsession with distributing his toxic newsletter. Tom Perrotta said that he initially envisioned Matt as a bigger part of the book. On the show, Matt evolves into a much more compassionate, nuanced character over the course of the season. See more
Dear Kevin, I need to say goodbye to someone I care about, someone who's still here, so I'm saying it to you. You were good to me Kevin, and sometimes when we were together, I remembered who I used to be before everything changed, but I was pretending. Pretending as if I hadn't lost everything. I want to believe it can all go back to the way it was, I want to believe I'm not surrounded by the abandoned ruin of a dead civilization, I want to believe it's still possible to get close to someone. ...