The title of the book—Tropic of Cancer—says it all. Miller is living in a place where disease and discomfort are the norm. And you know what? He seems to like it that way. It's all part of life's great majesty: birth, death, hunger, disease, aging, loss, and death. Bring it on. Plus, according to our writer protagonist, suffering is what makes you a good artist, offering all sorts of rich material. The good news is that Henry and his friends seem to have a small degree of sympathy for each other's suffering… right?
According to the first chapter, Henry thinks that Jews suffer better than Gentiles.
Henry equates neurosis and suffering and thinks that creativity comes from both of them. Basically, he believes that you have to be a mental case to be a good writer.