just read that people think cyrus died from sepsis/OD/shock/whatever and his conversation with zee is a hallucination. i understand why. him literally dying would be a beautifully terrible tragic irony-- he spends the whole book yearning for a meaningful death only to die in a completely ordinary way. the coda is there to say that the world will simply move on.
however, for my sake, im choosing NOT to believe that. im choosing to believe that it was a sign from god, something for him to stop the his fixation on martyrdom and his mother, a reminder that life is actually worth living. the death that occurs is more the death of his focus on martyrdom, and the "hallucination" is an invitation to a new thinking/philosophy. he chooses to live, he chooses zee, he chooses sobriety. and then the coda goes back to the beauty of an ordinary life.