One of the most, in a weird way, encouraging things a director can say to an actor - I know this as an actor - is when you ask them a question, they say, I don't know - 'cause it means there's some space there for you to find out. And it means that there's going to be a process.
I never talk about 'Harry Potter' because I think that would rob children of something that's private to them. I think too many things get explained, so I hate talking about it.