do you agree that this novel is about "the painful search for self"?

I really think the overriding theme is not so much the search for self but rather the search for belonging. All the characters in this novella are isolated in their own ways, even George and Lennie. The dream of all the characters is to find a place where they belong and are loved. In this sense there is a search for "self" but only as far as it involves sharing and being accepted. Put any of the characters in this context and you come up with the same motivations. All of them want a sense of permanence.They all want to belong, be loved and be accepted.