My first nano was an abject failure. I had no idea what I was writing, and by the time I got to the plot, I was 3/4 of the way through it. So then it felt like I was writing a whole new story. I got to about the 33k mark and that was it.
But years later I started using Scrivener. And I saw clear as day how nothing kills a story or a scene more than carrying on in the scene after it completed that thing it was supposed to do. Each scene is supposed to do one thing for your plot, and when that’s done, you bridge to the next scene that had the one point it was supposed to do, and so on and so forth until you reach the end of your book.
Once you realize that after you made your point you’re supposed to move on to the next scene instead of dawdling in the past scene, you don’t have parts of your book where your main character eats dinner, has a shower, drives home, all the useless filler that doesn’t add to the plot in any way but when you’re writing in a word processor with continual lines, you don’t see where the scenes naturally should begin and stop.