Why is Huck amazed at Jim's mourning his home and family?

Huck has never had a real family so he can't understand Jim's mourning.Huck remarks that Jim cares almost as much about his family as a white person would (this statement actually wasn't meant to offend). Jim is racked with guilt over his daughter Elizabeth. He had admonished his daughter for not closing a door unaware that she was deaf. This shows Jim to be a very sensitive and loving man.