The Canadian novelist Robertson Davies did not just use notebooks as a literary device in some of his novels. He also kept notebooks of ideas, characters, circumstances and other details. Apparently, he always carried one with him and constantly took notes. As do many people who keep paper notebooks, he numbered the pages. But he went further and gave every entry on a page a number, so that he could refer to it by a combination of numbers and letters: 10A, 24C, 45B and so on. That way he could refer to notes that he later found to belong together, that is, were relevant for a particular character, for instance, in an efficient way.
He seems to have viewed the human mind as a kind of "catchall"-notebook. Thus we find in his very first novel: "You like the mind to be a neat machine equipped to work efficiently, if narrowly, and with no extra bits or useless parts. I like the mind to be a dustbin of scraps of brilliant fabric, odd gems, worthless but fascinating curiosities, tinsel, quaint bits of carving, and a reasonable amount of healthy dirt. Shake the machine and it goes out of order; shake the dustbin and it adjusts itself beautifully to its new position." This view seems to be quite independent of his Jungian fantasies which I find quite unpalatable.