A/N: Okay after reading you guys reviews i realized that there was some confusion. In one of the previous chapters i explained everything so I'll do it again:
1. When Ozai burned the side of Zuko's face in the Agnai Kai, that event was so traumatizing and painful that in the show Zuko went into a mini coma. In the show he woke up after it happened on a ship with Iroh and his face bandaged. So....the same thing happened in my story except that the memory of his father doing that was so horrible that it blocked the memories of what happened earlier that week. so that means that Zuko doesn't remember his bday party where he met Katara. Get it?
2. As for Katara and Toph recognizing him, they don't know that Prince Zuko was banished. They don't know that he has the scar. They have no idea about anything that happened after that night because the war has started.
3. Also that night was two years ago!! And Toph only saw Zuko for a couple of seconds. Katara was only with Zuko about two hours. Their memories aren't perfect! Katara has a vague memory of what Zuko looked like exactly because she hasn't seen him in two years, and Toph well didn't really think too much about him. lol
4. Zuko has changed a lot. Obviously he has that scar that covers a good part of his face. Then he cut off hit topknot when he left his nation. So when he met Katara he had a flawless, unmarred face and his hair was in a topknot. Now he has that scar and his hair is all shaggy and grown out like in book three of the series.
I hope that clears up any confusion and if you have any more questions don't hesitate to ask through revie because i dont check my email. :)