On the page it's like Frankenstein's monster

Danny Rubin is a screenwriter whose credits include "Hear No Evil," "S.F.W.," and the cult classic "Groundhog Day," for which he received the British Academy Award for Best Screenplay and the Critics' Circle Award for Screenwriter of the Year. He has taught screenwriting at a variety of universities and organizations, and is currently the Briggs-Copeland Lecturer on Screenwriting at Harvard University.

His take on the art of screenwriting:

Writing a screenplay is not so hard.  That’s all about knowing where the margins are.  Writing a good screenplay is almost impossible.

Part of it has to do with being original, trying to do something that feels fresh when there have been so many movies made and also particularly in Hollywood, a tendency to try and remake the same movies over and over again.  So, it’s writing a movie that’s original that becomes really difficult and there's something very formal about the enterprise of writing a screenplay.  It can’t be longer than two hours. 

So, the kind of story you tell, whatever it is, it has to be as engaging and as exciting as possible within that one and a half to two hour period and that forces certain kind of conventions on you.  Places where we really want to have them gripped in the story by here or else they’re going to leave or change the channel or walk out of the theater.

There's a certain kind of efficiency built into screenwriting that’s very elegant, but that makes it as hard to craft as a very finely crafted piece of sculpture, furniture, something like that.  And making it all come alive when you just start putting together all the pieces of things that you visualize that would wonderful.  It all seems in your mind to be wonderful, but then when you look at what you’ve created on the page it’s like a Frankenstein’s monster.  You’ve got a head, you’ve got the hands, you got the feet, you’ve got the body.  You’ve thought of everything and when you look at it, it’s still just a bunch of dead meat lying there on the table and you're trying to get a pulse to go through the thing.