Sokka didn't want to face anyone after the debacle that his speech had been. He wanted to sit and stew about what a failure he was, and not talk to anyone.
But when Aang approached him, he found himself spilling everything out. And Aang – the silly twelve-year-old – suddenly became a strong, confident leader.
"Your moment of truth isn't going to be in front of some map. It's going to be out there on the battlefield."
On their way to the dock, Sokka whispered, "Do you really think I'll be able to prove myself?"
"Sokka," Aang said seriously, "You already have."