In the order of the Haggadah, the rebellious son who questions everything sits before the son who has nothing to ask.
Because if the rebellious child has questions, it's because something touches him, tells him something, maybe even bothers him.
But a fully capable human being who has no questions about the Torah and God is stuck in his place.
Perhaps he is a good, observant Jew who does good deeds and never sins. But he has no sense of spirit or meaning in his life, no sense of transcendence.
He too must leave Egypt and find something higher.
Second Seder, 1965.