Sometimes when you go walking in the woods, you're ducking under pawpaw trees and dodging gooseberry tangles, which is normal, but then you came to a big fallen limb all overgrown in a thorny tangle and it's blocking your way. So you have to backtrack, or go off to the side until you find a way around it, and then you move forward again. And then you come to a place where the hill is too steep and you don't want to slide down the thing on your butt, so you backtrack and go off to the side until you find a way to go forward again.
That's what writing the beginning of this new story is like. I write for a little bit, but then I come to a halt and the story is just not going anywhere, okay, so what would happen if I backed up a few paragraphs and changed this? And then I go forward a little way, and then errk! Stop! This is not working. And then I'm like, well, instead of Eyestar standing next to the door fighting the grasshopper army, why not have the main character there instead? So I back up and rewrite that bit, and it is cool, and then I'm going forward again.
And just like walking in the woods, I know the direction I'm going, but I don't know what I'm going to see along the way so I keep my eyes open for birds and mushrooms and animal tracks and wildflowers and look for surprises. And despite the little trailblocks, or the occasional tick crawling up the inside of my jeans DIE EVIL TICK, I know I'm going to have fun while I'm out and about.