Writing goes on and the story moves ever forward towards the end.
But it’s a good idea to look back from time to time. To read, or at least to scan, what’s been written and you might notice something rarely seen in real life: the future changes the past.
When I look back and read what I’ve written, sometimes there’s a scene that’s not suppose to happen, or it should happen differently, because of some other scene that I’ve written later on. So I change it.
This means, of course, that when the story finished, it’s far from ready. As an example, after Truths, Half-Truths and Lies was finished, I read (edited) it again (and again) and it ended up having thousands of more words.