He was in shul next to a bar mitzvah boy who was about to go up to the Torah scroll for the weekly Torah reading of Lech Lecha.
The boy said to him, "What question does Rav Kook have about this parshah?"
My friend couldn't think of any. He said, "Rav Kook has questions dealing with all of the parshas and with all parts of the Torah. But his main question is: why is it that, although everything is filled with God's light, we don't see it?"