How faithful to his book did you feel you had to be?
I wanted to be faithful. There was a lot of information in the book but also we could ask John whatever we wanted when we were first doing the screenplays. When I did my recent version of the screenplay, John had died. But we'd asked him a lot and spent a lot of time with him and got to know him really well. It was always going to be very much based on his truth.
So this is how he really was?
Joaquin isn't really doing his voice. He had a very soft voice. Puns were the source of his comics so he would always be trying to figure out a pun and how it could work and he might be mumbling the pun to try and figure it out. And he was always trying to think up jokes. If you were doing something in particular he might make a joke about it or find the joke within whatever it was you were doing. He was always working, in other words, I guess.
His comics caused controversy, was he a deliberate provocateur?
Yeah, of course. His cartoons were provocative. But that's something in the film that we're not really centring on, we didn't show him doing that so much. Sometimes he is but not in the way that he really did.
Like, his little dog was a dachshund, and when we went outside his house John was telling his neighbour that his dachshund might have a fight with their German shepherd and hurt him and beat him up because it was funny.
The dachshund was so tiny. It was a joke but the neighbour didn't think it was funny, which made him insist more. So John kept going, "Oh yeah, my dog will kick your dog's ass". He would push it, you know.
By keeping that stuff out, you've focused on his alcoholism and addiction. Why?
I knew that I couldn't tell the whole story. When you try to tell the whole thing there's too much story. I was used to tearing down stories in other projects and that's how I found the way to get a certain essence of what he was all about. His whole life was centred around stopping drinking. Mostly because he didn't think he would have lived and never would have been a cartoonist if he'd kept going. So he felt that everything that he had was based on that event of quitting. So we decided to tell that story.
Joaquin Phoenix was really speeding around in that wheelchair. Was that a custom chair you had made for dramatic effect or is that really the top speed?
That's the kind that he had in our photographs of John. He had a fast one. I think they make them so you can get away from things that might be coming at you. They're not super slow because then you'd get hit. They're quite fast, they can go 20mph (32km/h). Some people put different wheels on and drive in traffic.
Lowdown
Who: Gus Van Sant
What: Don't Worry, He Won't Get Far on Foot
When: In cinemas today