In this sentence, what do the quotations mean about Hucks attitude?

Huck's changing his attitude about the way he see slaves.......... that Jim is human, with real feelings, just like him.

"I knew what it was all about. He was thinking about his wife and his children back upriver, and he was feeling miserable and homesick. He’d never been away from home before in his life, and I believe he cared just as much about his family as white folks do for theirs. It doesn’t seem natural that he would, but I guess it’s so."