But with OC there's no canon to direct you to the this you do want. And if I slog on with my story, determined to write my way through in spite of misgivings and reluctances like the Big Girls do, I merely end up creating a chunk of unsatisfactory canon that I'll have to stick to later on. In fic as in life, the roads not taken vanish if you don't take them; the road you're on becomes the only one there is. You can go back a few blocks, maybe, but you can't miraculously start again on the outskirts of town. Let us say, when you type ten words a minute you can't start all over again, or at the least are reluctant to.
This annoys me. 'Grendel, you create the world, moment by moment.' Yeah, and it sucks.
(Sure, yes, plot everything in advance and give orders to your characters that they are to do only and exactly what you say. IME this sucks both the life out of them and the fun out of writing, because my left brain is a really trite story teller and produces cardboard cutouts when left to its own devices. I need a certain open-endedness in the plot-- a goal to get to with the route not marked- so the right brain can come in and do its magic stuff as I write, the stuff that makes me say Oh wow. I write for myself, and I insist that I astonish me. Fair's fair, after all.)