When I wrote that section, I was especially interested in the twin ideas of grief and haunting, since I imagined that Part 2 would begin with a funeral and end with a ghost. I didn’t have well-formed thoughts on the matter, just an intuition that these two experiences had something in common. For example, both grief and haunting tend to isolate a person. Grief is often accompanied by the desire to withdraw, to not commit to anything so that it can’t be lost too. The essential weirdness of a haunting sets the hauntee apart from the rest of the world, even people close to them. To be haunted is to be singled out, separated from the pack. There’s a feeling in both cases that no one else can possibly understand what one is going through, and that to try to explain it would be hopeless. And both grief and haunting can be slightly narcissistic: you might be in a very dark world, but you are at the center of that world. Hamlet’s grief is initially portrayed this way, disproportionate to the circumstances and self-indulgent. While he claims, "I have within that which passeth show," Claudius dismisses it with: "To persever/In obstinate condolement is a course/Of impious stubbornness...'tis a fault to heaven/A fault against the dead, a fault to nature/To reason most absurd: whose common theme/Is death of fathers." Claudius has an agenda, we know, but he’s correct, if overly dispassionate.
By the way, an interesting book to read in this regard is C S Lewis’ A Grief Observed, a remarkable account of Lewis’s state of mind after his wife died from bone cancer in 1960. I first encountered it while drafting Part 2. Joan Didion’s highly acclaimed The Year of Magical Thinking is also beautiful and harrowing (though not a research source for me). What I took away from both is how particularly grief manifests itself. Grief is not a uniform experience with a reliable set of symptoms, but a sort of pall that entwines itself in the smallest perceptions and emotions of the sufferer.