"I'm not going to write because I feel like I don't know my story and my characters"
Well that's a fair enough point but how are you going to know your characters by never writing. For example the first pilot I wrote, I thought it up for ages, maybe 6 months and I did outlines, scene for scenes and character grids and when I got down to it, only 1 out of about 6 characters felt right. But then I had a first draft to work on and I could go back over it till the characters all improved. The screenwriter in question has nothing, he's wasting time like I did.
This isn't a naive standpoint either, I'm not on a high horse, most top screenwriters don't outline.
Two quotes (that I'm paraphrasing) I've heard over the last couple of weeks.
George Lucas when asked does he outline said "Hardly ever, I do what my friend Francis (Ford Coppola) taught me to do, lock myself in a room and just get through it, the first draft is going to be terrible but writing is rewriting so you might as well get that first draft out of the way as fast as you can"
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The second being Fight Club scribe Jim Uhls who I'm lucky enough to talk to via the net quite regularly, he says "I don't outline because it's like shooting your load early, I like to explore and outlining ruins that."
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I'm not for one second saying neglect planning but there is a distinct difference between a few grids to outlining every scene and spending months on the character's back story. Like Uhls said, "explore" you'll find your way.