Someone who knows all the laws of Pesach is still required to ask questions, and scholars on their own at the Seder are required to ask themselves questions. But why?
At a certain level, the questions serve as an external pretext to refresh the memory in order to raise the level of consciousness concerning the Exodus even for those who have passive knowledge of the information. At another level, someone who asks himself or herself questions and then answers them, can delve deeper and discover new aspects of knowledge and self-knowledge.
From the video below on down, find fascinating articles and essays about Pesach from scholars of the Shalom Hartman Institute, including David Hartman and Donniel Hartman.
David Hartman Video: Pesach: The Radical Uncertainty of History