Toph's real life changing field trip comes when Zuko hears about her parents and, as someone who had a parent that didn't understand them (that didn't w a n t to understand them), he relates. But Zuko doesn't teach Toph to hate her parents. And Toph doesn't try to make Zuko forgive his father. They just come to the mutual understanding that it isn't about making others happy. Hell, it isn't even about being happy with y o u r s e l f. (1)
But finding a place you c a n be happy in. Cause even if others are happy with you, there's no guarantee that you are. And even if you a r e happy- who's to say those around you won't make you feel bad about it? Even if you don't care, lack of acceptance and rejection hurt. But if you find a p l a c e you can be happy? Then even if you're sad, you'll at least be comfortable. You'll know you're accepted. And you'll have a support system that can make you happy with yourself again. (2)