This one's for you when you've crossed into the editing stage with your book. Here, it's time to focus on what your book is *really* about — and then cut everything out that doesn't suit.
You may discover the second half of your book is written in a completely different style than the first. Be consistent.
Or maybe there's a story in there you absolutely love. It's tender and lovely and makes your heart break just a little — but it doesn't serve the purpose of the book. Pull it out. (But be sure to save it in your scrap file to revisit later.)
This is where the hard decisions get made. This is where discipline levels up. This is where you have to stay focused. You can do this.