"Our son’s changed Berk for the better!" -Stoick
"You have the heart of a chief, and the soul of a dragon. Only you can bring our worlds together.” - Valka
"… MAYBE YOU JUST DON’T SEE IT YET."
Maybe. You. Just. Don’t. See. It. Yet.
Astrid sees it. Stoick sees it. Even Valka sees it. This is it. This is the film.
A movie literally filled to the brim in pointing Hiccup as chief and how he’s the only one who can’t see it. He is the best option for chief. He is a chief unlike any other, a chief for this new world order that he created. This film is the middle-leg of his journey.
Hiccup still has a very skewed idea of what it means to be chief. He associates being a chief with his father; the two are interchangable in his mind. To Hiccup, Stoick exemplified what being a chief was about and it was daunting.
"I’m not my dad."
"I think you’re missing the point, Hiccup.”
Hiccup is literally the only one who doesn’t see that he already is a chief. BERK sees it. Astrid sees it. Stoick sees it. Hiccup is commanding, authoritative, intuitive, and takes initiative. He makes decisions and incorporates them.
*That right there is the biggest difference between he and his mother. As well as his greatest similarity with his father. Valka complained of “I tried to get them to see another way” but Hiccup FOUND them, Berk, another way. Valka “TOLD” humans what was wrong, Hiccup “SHOWED” them how to fix it. That’s an essay for another day.
Pay attention to Hiccup when his mother gives him the “We’ll learn about dragons together” speech. Hiccup’s “agreement” is obviously of different mind than hers. They are not on the same page; this isn’t even an interpretation choice. All of Hiccup’s interactions with his mother are cleverly ambiguious.
Valka is speaking of Hiccup joining her. Hiccup isn’t. He’s already thinking of how to incorporate what his mother knows into joining humans and dragons. He’s thinking Valka, and her dragons, will come to his world, not the other way around.
Hiccup doesn’t want to leave Berk and he doesn’t want to be his mother. He doesn’t want to be his father either. He’s somewhere in the middle—that was his struggle, that he had no example to follow—and everyone but him sees it as a good thing.