Why do I quit halfway in? I get tired. It's not fun anymore. The story kind of sucks, and it's hard to sit down every day and spend several hours eating from a giant bowl of suck. And most of all, like the kid who spends hours preparing plastic armies for war, I enjoy setting things up more than I enjoy the battle itself. To finish something is to be disappointed. By definition, abandoned novels are more promising than completed ones.And it's true. Starting, for me, is the fun part. I like introducing characters much more than I like giving them purpose, destiny, and fulfilment. But at the same time, I've passed the halfway mark. I've started something that deserves to be finished. If I've written 25,000 words in half a month, I can certainly write 50,000 in thirty days. Here's to the second half!
You have likely reached the moment in this insane endeavor when you need a rock-solid answer to the question of why, precisely, you are trying to write a novel in a month. You have likely realized that your novel is not very good, at least not yet, and that finishing it will be a hell of a lot less fun than starting it was.