Exceptional writing day

Yesterday was an exceptional day for writing. I was able to write until late in the afternoon when visitors arrived. If I could get that many words on paper every day, I could finish a novel in as little as six months. It was a day when the characters took over, and it was almost like the dialogue was dictated to me by them. I have often wondered why days like yesterday occur. I suspect it is my mind processing ideas until they gel. I also suspect today will be devoted much more to editing.