I teach for the Book Trust, which promotes reading and writing with children.

They seem much rarer now, those auteur films that come out of a director's imagination and are elliptical and hermetic. All those films that got me into independent cinema when I was watching it seem thin on the ground.

Somewhere the glamour has gone because of the industrialization of this whole process. I wish it [filming] felt as magical and glamorous as people want it to be, but it feels like a routine people are going through.

I went to meet Joe Johnston, the director, and he's charming. I've been very lucky. Most of the directors I've worked with are charming. But Joe's a particularly charming man, and he showed me lots of designs and, rather memorably, welcomed me to the Marvel Universe.

But I think the children of actors share a certain pragmatic approach. One is denied some of that 'running away with the circus' element of being an actor.

There's not a huge pile of scripts at home. It's what happens to be on the table at that moment with your availability. And then you have no control over when these things come out.

We're blessed with, as we were on 'Harry Potter,' lead actors who are amazingly grounded people.