Sacks's lifetime of journals

I started keeping journals when I was fourteen and at last count had nearly a thousand. They come in all shapes and sizes, from little pocket ones which I carry around with me to enormous tomes. I always keep a notebook by my bedside, for dreams as well as nighttime thoughts, and I try to have one by the swimming pool or the lakeside or the seashore; swimming too is very productive of thoughts which I must write, especially if they present themselves, as they sometimes do, in the form of whole sentences or paragraphs.

. . . The act of writing is an integral part of my mental life; ideas emerge, are shaped, in the act of writing.

My journals are not written for others, nor do I usually look at them myself, but they are a special indispensable form of talking to myself.

Oliver Sacks, On the Move: A Life (New York: Alfred A. Knopf, 2015)

Keeping a journal helps writing

"My dear madam, I am not so ignorant of young ladies' ways as you wish to believe me; it is this delightful habit of journaling which largely contributes to form the easy style of writing for which ladies are so generally celebrated. Everybody allows that the talent of writing agreeable letters is peculiarly female. Nature may have done something, but I am sure it must be essentially assisted by the practice of keeping a journal." 

Jane Austen, Northanger Abbey, ch. 3 (Mr. Tilney speaking)

Austen's use of the word “journaling” in Northanger Abbey astonished me when I saw it: I had thought that using “journal” as a verb was a recent development. When my editor checked the quotation [I used it in a Law Library Journal column], though, she found editions in Google Books that used “journalizing” or “journalising,” so Austen might not have said “journaling” after all. (The OED does have an instance of someone else using “journaling” in 1803, so I can still remark on its being such an old usage.) And the point remains: writing in a journal develops your ease in writing.

Not everyone is like Sedaris

It sometimes helps to remind myself that not everyone is like me. not everyone writes things down in a notebook, and then transcribes them into a diary. Fewer still will take that diary, clean it up a bit, and read it in front of an audience.

David Sedaris, "In the Waiting Room," in Disquiet Please: More Humor Writing from The New Yorker (David Remnick & Henry Finder eds., New York: Random House, 2008), p. 513 (Kindle location 9044) (orig. pub. 2006)