Sokka: What's wrong with you?! We don't have time for fun and games with the War going on!
Aang: What war? What are you talking about?
Sokka: He's kidding, right?
...
Aang: Isn't there someone in your tribe who can teach you?
Katara: No. You're looking at the only waterbender in the whole South Pole.
Katara: This ship has haunted my tribe since Gran-Gran was a little girl. It was part of the Fire Nation's first attacks.
Aang: Okay, back up. I have friends all over the world, even in the Fire Nation. I've never seen any war.
Katara: Aang, how long were you in that iceberg?
Aang: I don't know. A few days, maybe?
Katara: I think it was more like a hundred years!
Aang: What?! That's impossible! Do I look like a hundred-twelve-year-old man to you?
Katara: Think about it. The War is a century old. You don't know about it because, somehow, you were in there the whole time!
Katara: It's the only explanation.
Aang: A hundred years! I can't believe it.
Can I just talk about how devistating this moment is. This is the the face of a sweet inocent child realizing that everyone he loves and has known, his whole life and world, is gone. He has been go for 100 year.
And not unlike Rip Van Wrinke, he wakes to find the world a very differnt place then he remembers.