I never told my father I loved him before he died, and I have a lot of issues about that. They're all swimming around in my head, in my heart, unresolved, and in a way it felt fitting to dedicate the film to him.
What's fascinating is that when you write a script, it's almost a stream of consciousness. You have an idea that it means something, but you're not always sure what. Then when you get on the set, the actors teach you.
I have three kids who like Harry Potter so I was sort of aware of it. You can't really move from it: it's on buses, in stores, it's everywhere. One of my kids has read the books; the other two are too small but they like the movies.