What is the theme in High Fidelity by Nick Hornby?

Learning to like oneself is another theme in the book. When Laura leaves, she forces Rob to reevaluate his life. For the first time in a while he has to look outside his insular world and at why he has caused his girlfriend so much pain. Initially he seems to decide that he cannot help it and that is just the way he is, but Hornby presents this as part of his problem. He has become so comfortable disliking himself, that along with his hobby, he has allowed it to define him. Not until Laura embarks on an affair with his ex and hated neighbor Ian Ray does he decide that enough is enough and he must win Laura back.