My book War Horse is a case in point. It’s been made into this extraordinary play with the horses being played by giant puppets. If you go to the theatre you can see 1,000 people coming out of the performance and a large proportion of them have been crying their eyes out for the last two hours. They identify with the great sadness of the First World War. It’s a release for them to cry in the same way it’s a great release for us to read a book and feel both grief and joy.