"First off, my parents got divirced ten years ago because of me. My being born changed everything for all of us, in every way. My dad didn't divorce my mom, or my sister, Cindy, or my brother, Paul-he divorced me."
I think this quote from my book is important to the story because it begins to "lay the foundation" of the whole "theme." Shawn's father couldn't handle his condition, so instead of trying to work thing out he just decided to quit. He even moved out because he couldn't handle Shawn and his condition. He still sees Shawn from time-to-time, but onlywhen goes home to see his wife, and his other two kids.
"There is one final bad-news punch line to my life. The bad news is complicated, difficult to explain. In a nutshell, it's that I'm pretty sure that my dad is planning to kill me."
The passage is important because Shawn has sort of figured out how much of a hard time his dad is having with his condition. But just because it "hurts" him to see his son go into a seizure, he doesn't need to kill him. If he really loves his son,like he says he does, he doesn't need to kill him. Shawn has now become terrified whenever his dad is around, because he doesn't want to die. He loves life even though his life is limited in a way.