Patience means that I have faith and trust in where the writing is going, so perhaps if I am impatient, it is an expression of loss of faith. If I must know now, this second, how each chapter is integrated, how the whole looks, and have all the plot figured out and answered, and have no more questions to ask myself as I go, what will there be left to discover as I write?
E. M. Forster was one of many writers who claimed to discover what the writing was about as he wrote, and I think that serendipitous writing is probably what keeps me interested in the project. If I had the entire thing plotted ahead of time it would no doubt bore me to death. On the other hand, there's a lot to be said for bringing a map with you on your journey so you don't get completely lost.
That's where it's helpful to have written the structure ahead of time so that I can go back and review what my initial plan was. What I had in mind for this story when I got started helps remind me of where I want to be in the writing process, and I refer back to it often. But just now I'm trying to figure out what the next chapter should be about, although it's probably best if I go back instead of going forward, and finish off one of the earlier chapters I've left unfinished for the moment. Recursive writing; it's how I write--go forward, go back, polish, pick up a new idea in a chapter farther on down the line, go back and polish something from early days. It's terribly non-linear, I'm afraid.