At Netflix Queue and at Interview, Iain Reid and Charlie interview each other. Both worth checking out!

From Netflix:

CK: I wanted to address that concern of the twist ending by not making it a twist ending. Movies are different, in my estimation, than books, in that you’re taking something that can be enigmatic on a page, and you’re making it concrete: Now you’ve got actors and a set, and you’re saying, “This is what it looks like.” ( Source )

IR: Yeah, which is why there’s so much dialogue, especially at the beginning. People talking about the end of the book have sometimes said, “Oh, I figured out the twist halfway through.” In my mind, I’m like, What do you mean, the twist? That’s not how I set out to write it. If the end is surprising to a reader, I like that. But again, this isn’t a psychological thriller with a twist ending. It’s just a book, and it tries to tell a story in a way that’s a little bit more unusual. I feel like the film also does that. It’s not necessarily about the end; it’s about everything that’s happening and the questions that arise.

From Interview:

KAUFMAN: When you think about the book now, do you picture the characters as you pictured them when you were writing it, or as they appear in the movie?

REID: I haven’t re-read it because I always have a hard time re-rereading things that I’ve written after a while. But that’s interesting. I don’t really have a particular image in my head of characters when I’m writing them.

KAUFMAN: You had a physicality. Heights and that sort of thing.

REID: In the book, there really isn’t all that much physical description. For Charlie, and for you, like me, the internal world is more interesting, so I really didn’t have a set vision for any of the characters. What’s in the book is really all I had. I had Jake as being a little bit taller and kind of ganglier, and his girlfriend being a little bit shorter. And then people who read it can come up with their own descriptions. There’s something about Jessie and Jesse together, their chemistry really is amazing. And I think people are really going to appreciate that when they watch it.

KAUFMAN: The reason I asked that question is because when I think about original screenplays I’ve written, people will say, “Are Jim Carrey and Kate Winslet who you thought of when you wrote Eternal Sunshine of the Spotless Mind?” And the answer is obviously no, because they weren’t cast at that point, but that’s who I picture as Joel and Clementine now. I can’t really even remember what I pictured them like beforehand. If I forced myself, I could go back to it and realize, “Okay, this person was based on this person.” But I don’t picture those people anymore.

REID: I guess the only one for you would have been John Malkovich when you were writing Being John Malkovich.

KAUFMAN: I actually pictured Craig [played by John Cusack in Being John Malkovich] as somebody very small. I imagined someone like myself. (Source)