Interesting to see the comments about bookshelves because I owned a specialist book business for 25 years and I used to find that some customers always managed to put a book back exactly where it had been on the shelf, whereas, a great number either did not slot it back somewhere on the shelf or even left it on the floor. I never did work out why they left them on the floor, however, I and my staff used to spend quite a bit of time sorting them out. Fortunately, none of us suffered from any syndrome --imagine what that would have been like!
Anyway, suffice to say that it is an individual choice how you use your bookcase so do as you please because it doesn't really matter!