A very satisfying part of my job is sorting the books back into order that YOU the general public have just shoved back in any old place.
Fiction should be in author order, but we also split it by genre and quick read displays are in no order at all, making it difficult to find specific books - it would almost be easier to sort them in colour order. Not all authors fit neatly into one genre: Charlaine Harris pops up in Horror, Supernatural Fantasy and Crime, for example and China Mieville is all over the place. I'm not entirely sure which shelf my putative best-selling novel will eventually end up on.
So the precision of the Dewey decimal system is very welcome in non-fiction. That doesn't always mean you can find exactly what a borrower wants: if someone wants a picture of a unicorn you’ll be all over the place - in mythical creatures, nursery rhymes, fantasy art, and end up in heraldry.
Now I've got the gist of the system the world feels more organised, but I still worry about stuff: in the health section: the back ache books are on the highest shelf, osteoporosis on the lowest, yet the yoga ones are perfectly easy to reach – when it should those you have to stretch for. The dementia books have been abandoned on a nearby table but at least the books on OCD are returned to the shelf in perfect order.
In the children’s library they have whole sections on volcanoes and dinosaurs, and at least half of the books are something to do with underpants (*sniggers*). One day one of these little cherubs will be all grown up and sitting behind a big desk saying: "That library assistant changed my life. She encouraged me to read and that’s what got me where I am today: Professor of Underpants."