Disclaimer: I don't own Avatar: The Last Airbender.
Sokka was thinking. He was thinking deeply and profoundly, something which people did not suspect him of. However, it happened quite often that he would consider something. Like now. The object of his thoughts was sitting opposite to him and trying to glare his eyes out.
I wonder if he practiced that? Sokka wondered, the seriousness perishing from his thoughts.
He remembered himself doing just that – practising various intimidating expressions while staring into the water or into a mirror. He did need to know if he got them right and it seemed rather natural that another young man would worry about it too. A warrior couldn't look like some pansy, could he?
A moment later he was back to his original thought and nearly ready to ask Zuko a question. Still, he decided against it. It wasn't like the other would answer and in all probability Sokka would be risking getting torched or something similar. Instead, he settled for something more neutral.
"Why do you carry swords?" he asked.
"Why do people carry swords?" the prince growled back. His tone was indicating clearly just how stupid the question was.
"You're a bender."
This time Zuko didn't say anything – he only glared.
Sokka nearly smirked. Even if Zuko didn't reply verbally, his reaction was enough of an answer. But he wasn't about to say what he figured out. He was neither stupid, nor did he enjoy getting hurt.
He wasn't sure when this thought first occurred to him, but it didn't want to leave him for a while. It made him stop giving Zuko suspicious, hostile looks. Actually, it made him feel related to the banished prince. After all, they were in similar situations.
Who needed a non-bender and somebody who was just above average, when you had prodigies and experienced veterans? It wasn't always like that, but Sokka guessed that sometimes they both felt unnecessary.
I'm not sure if I got Sokka right, but I was aiming for a serious mood and seriousness isn't very Sokka-esque, I guess. Anyway, I do think that those two have certain things in common.