Complex sentence: Harry believes that he is better than his surroundings and fails to understand why he cannot be recognized as such, which raises the idea that in order to rise above a group one must first become one with a part of it.
Split into simpler sentences: Harry believes that he is better than his surroundings and fails to understand why he cannot be recognized as such. This raises the idea that in order to rise above a group one must first become one with a part of it.