What are some questions you could ask Piaget about his theory if you could meet him in person?

Of course, my questions would be different than yours, but I would ask why Piaget was interested in children.  Much of his early work was with water snails, and it's not a logical jump between studying mollusks and children.  Piaget also looked at stages of development.  I would ask him why he created these stages and if they are concrete, or if children can move between one stage and the next.  I would ask him what his opinion was of social constructivists such as Vygotsky and if his theories discounted the role that others play in a child's life.  I would also ask him if he saw children's minds as a "blank slate" at birth or if the children had the capacity to learn certain things and that this capacity was unlocked at certain periods in a child's life.  I would also ask him what he thought of children that we regard as "prodigies" who can learn complex material at an early age.