Who do we make friends with? This is a hard question as friendships are formed for any number of reasons: To keep the piece, because we want something, have a need for something or like a persons attitude towards life. But what happens when we discover that we are truly by ourselves, when even the ones you thought you knew can't even remember your birthday. This is when we are described to have "hit rock bottom". In the novel both Hart and Micheal Hit the "bottom". When Hart lost his leg, Also when Mitsy would not speak to him for what happened to her father. When Micheal found out that his wife had died, also when he is found alive after the boat crash and Sadako is left missing. .
It is described in the book that for a period of time they were left in almost darkness; they cut themselves off from the rest of the world.
"Eventually my father fetched me home in the black Nash, and I fell into a sad, subdued, almost pleasant kind of dreaminess. I thought that the world was full of busybodies and I retreated in the face of all that good cheer. I had no need of speech or action but curled up with books and daydreams in corners of the house where the filtered light barley caught the dust motes and no sounds penetrated".
I also think that Garry Disher was trying to get across what having no friends or hardships can create and cause.
When we make friends we keep things secret from each other and do not tell "home truths", as we do not want to lose them. But after a while being in each other's hair has to permit things to either slip out or are told to each other. Enough time to notice one or a few things that we dislike in a person that we did not see before is enough time to break a friendship. When looking at friendship you notice that when we seem to find a fault in someone it becomes everything, we strive to find more and eventually we grow apart. I recently read another book on psychology it said that you could not meet the same person twice.