Never argue with you muse.
You are sitting down to write your novel, and you have a thought on where you want the book to go. The character is in your head, you know what you want to happen. You start typing away, or writing, and WHAM! You just can't get it down on paper. No matter what you try, it just won't flow. You're trying to have your characters do, say, be one way, and they are telling you "NO! I want to do this!"
That my friend, is your muse talking. Don't argue, because 99.9% of the time, you won't win. Just let the muse guide you, and the story will flow.
Wishing you a blessed day,