I'm up to 20,000 words and already I'm altering the synopsis to keep up with the way the story is going. Is this bad? I don't know. I read on a lot of blogs that authors use ennegrams, horoscopes and strict character analysis prior to starting a work while others just sit down at their computer and think, "Let's see what happens today."
Some say you have to know your character in detail before you begin, because they drive the story. I agree with the second half of the sentence, but not necessarily with the first. I start with a rough outline in my mind of where the story will go and who the characters are, but beyond that, they (and I) discover each other as we go along.
Hence the changes in the synopsis. Sometimes the characters just don't react the way I thought they would, and rather than force them into a mould they obviously don't want to go, I feel happier bending the synopsis around them. The changes are not huge. The goal will still be met; but it might be met by a different route than I first envisaged.
After all, you don't get to know a friend all in one huge gulp, do you? So why expect to get to know a character before you test them in different and possibly vexing situations?
Just as a footnote - our first taste of winter has arrived and it is quite a shock to the system. We have temperatures below freezing again yesterday, and forecast for tomorrow. Yesterday we walked by the river at Hexham and at midday the sun was beginning to catch the frost-rimmed leaves.
This was the view north across the river into Northumberland. If you click to enlarge, look through the trees and you might see the Roman Wall.
I'm kidding - you won't, but believe me, it is up there, about three miles beyond the river.