The story of Harold Fry and his unlikely pilgrimage began as an afternoon play for radio. For many years, I have been writing plays and adapting novels for 'Woman's Hour' and the 'Classic' series. So this was originally a three-hander play, broadcast one sunny afternoon on BBC Radio 4.
In January 1962, when I was the author of one and a half unperformed plays, I attended a student production of 'The Birthday Party' at the Victoria Rooms in Bristol. Just before it began, I realised that Harold Pinter was sitting in front of me.
I give my grandfather, Dr Harold Young, a forestry Professor at the University of Maine, full credit for my career path. He pioneered the use of aerial photography in forestry in the 1950s, and we think he worked as a spy for the CIA during the Cold War, mapping Russian installations.
'Perfect' is about a set-up that looks perfect from the outside - beautiful country house, beautiful wife and mother, everything where it should be - and the deep fissures that, in fact, lie beneath that. 'Perfect' was partly a response to the shock of my first book, 'The Unlikely Pilgrimage Of Harold Fry,' being a success.
If you look at Christmas movies, there are certain things in them that lend themselves to a 'Harold & Kumar' movie. In particular, the more out-of-this-world things like Santa Claus and flying reindeer.
Long before I was a writer, when I was just a haphazard reader and a dreamer of stories, I learnt about an influential book by Harold Bloom. 'The Anxiety of Influence', published in 1973 when I was five years old, is taken up with the terrifying influence of poets on each other.
When I portray Stabler, I have to shave every day and cut my hair every week! And then, I really like to change my looks for films like 'Harold and Kumar Go to White Castle' where I have the pleasure of playing the ugliest man in the world.
We are quick to stick labels on others - especially those who don't fit in with the norm. 'Harold Fry' is about a broken marriage; 'Perfect' is about a broken person. They are both about finding kindness where you least expect it.
I've always liked texts that you immediately understand. I suppose the playwrights who really speak to me are Edward Bond, Joe Orton and Harold Pinter. I've been in six different Pinter productions - I love the clarity of his language. He has this way of using words - there's a thrill to them.
I grew up on Harold Lloyd, Charles Chaplin, and Buster Keaton, and those were the ones who inspired me.