Zuko tries to pass on the knowledge he gained in his life to the next generation, in hopes they won't make his generation's mistakes. Finale spoilers
Echen was already bored, and getting annoyed. She'd spent the last week telling all of her friends at school how her dad was going to take her on some kind of secret firebending training trip. And, well, everyone knew that her Dad had taught the Avatar, and had even learned from some hidden master, like maybe the ghost of Avatar Roku, or a Sun Warrior, or even a dragon. It had made hearing about Li's trip to the volcano bearable.
Echen wasn't sure where they were, because her dad had blindfolded her. She just knew it was hot -- not the volcano kind of hot, but the outside kind -- and they were in a tiny little boat that rocked every time her dad poled it along. She could hear every time Heru in the back changed position. She didn't even know why Heru was along -- he wasn't a firebender.
"All right, you can take the blindfold off," her dad said. "And stand up."
Echen did, squinting in the bright sunlight. They were outside, in some kind of swamp or something. Anyway, they were surrounded by water and plants -- not what she'd expect for a firebending trip. Her dad had put on a straw hat, like the kind peasants wore -- or at least, actors who played peasants in plays. If the heat of the sun was any indication, peasants weren't dumb. Heru had even gotten out her parasol, and was using it for shade. She wanted to push him over and take it back, but her dad had chewed her out enough about picking on her older brother. He'd probably just take her back and not teach her anything.
Not that she was learning anything here. It looked like the kind of place a waterbender would practice. Not a firebender, especially a princess. "We're in a swamp," she said.
"It's a rice paddy actually," her dad said. "Most of the food that we eat in the palace comes from here. See those mountains in the distance?"
Ehcen turned, rocking the tiny reed boat. Her dad was sounding like Great-Uncle Iroh or the Avatar, which was unlike him. He actually seemed relaxed, and more like the kind of firebender who helped restore balance to the world than someone who always seemed to be too busy with /something/.
"Hey, sis! Watch it!" Heru said.
"I am!" she retorted. 'Yeah, I see the mountains. So what?"
"Rivers flow down the mountains, bringing water and ash to the fields. And the mountains block the wind, which makes the rain. All of those are the other elements. Look up?"
Echen did, shading her eyes. "It's the Sun."
Her father nodded. "Without the Sun, this place would be as empty as a cave. All life comes from the Sun's energy. All firebending comes from energy -- care about something, and you'll never have a problem calling the fire."
"For the longest time, we thought that fire was destruction -- that only anger and aggression could fuel fire. But any emotion can do it -- anger or joy or determination." Her dad seemed to be speaking to someone else. "That's a lesson everyone needs to learn. Non-benders, too, Heru. So I want both of you to listen to me."
Echen sighed reluctantly, sitting down again. Heru had put away his book as well.
The kids dashed off as soon as they set back to dock. Zuko sat down for a moment, letting his feet sink into the water. The old man next to him let his hat slide down and handed him a cup of tea. "I don't know how you can drink tea in weather like this," Zuko said.
"It is never too hot for a good cup of tea." Iroh took a sip of his. "So, how did it go?"
"I don't know if either of them were listening to me, Uncle. None of it came out right." Zuko said.
"Mmm... kids that age sometimes don't," the old man said.
"I just want them to grow up better than I did," Zuko said. "I don't want them thinking they have to compete for my attention, or that I'll only love them if they're perfect. But I can't get Echen to stop picking on her brother or bragging to her friends, or Heru to feel all right about not being a firebender."
"I think you've done more than you think," Iroh said. "You led by example, Zuko. They may be a bit rough around the edges, but they will grow up knowing their parents love them. It will do more than you think."
Zuko nodded. "Being a parent is hard, isn't it?"
Iroh nodded. "It is. And frustrating, and sometimes very sad." He glanced over, and Zuko remembered seeing him again in the shadow of Ba Sing Sei, and realizing that no matter what he had done, his uncle would always see him as his second son. "But the joys are worth it. You're doing a fine job as father, Zuko. Maybe not perfect, but no one is perfect in this world."
"Thank you, Uncle. You were a good teacher."