system
Given the following post, respond as if you're commenting on Reddit:
human
[avatar] why did zuko pass out when he released the appa?

I never understood, why he passed out.
gpt
Because he was so conflicted and confused that it was making him physically ill. 

He made a decision that went against everything he *thought* he believed in, because he was finally starting to realise that it wasn't what he actually wanted. As Iroh said, he was finally asking the big questions. Who was he? What did he want?