Rousseau lamented how long it took him to write, finding: "My scratched, written-over, muddled and illegible manuscripts bespeak the trouble they have cost me to write them. There is not one that I have not had to transcribe three two four times before sending it to the printer. I have never been able to do anything pen-in-hand, at a desk. It is on my walks among the rocks and trees, or at night, during my sleepless hours in bed, that I do my writing in my head and it may be guessed how slowly it all proceeds, especially for a man who has no verbal memory and has never been able to learn twenty verses by heart in his life. There are paragraphs which I have turned over and over in my mind for five or six nights in succession before they have been in fit shape to be put on paper."
Perhaps it would have been better, if he had committed the paragraphs to paper right away. See also Thinking on paper and the necessity of failure and Thinking on paper.