This is a good post for April Fools week, but I swear it's a real thing.
The photo below shows the "readers advisory" shelves in my library - the books patrons can use to find more books to read. Except, one day, a set of encyclopedias - copyright 1965! - suddenly just appeared on the bottom shelf, and staff have no idea where they came from:
Our best guess is a patron brought them in to donate, and when we said no, and our Friends group likewise wouldn't accept them for the booksale, the patron just snuck them into the library anyway and left them on a shelf.
This is especially weird because this particular shelf is not at all near the front door, and no staff saw anyone lugging an entire set of encyclopedias through the library.
But don't get me wrong - we've found far worse things left behind by patrons, so I don't really mind these. It's just, I don't know, odd. Like, the person wanted to donate them to the library, and even after being told the library doesn't want them - copyright 1965! - they sneakily left them there anyway. As if we wouldn't notice. Or as if just by accident some other patron would use them. More likely, the person just no longer wanted to deal with them, and dumped his problem on us instead of take them back home.
Public libraries are endlessly fascinating.