People that carry stuff back to the library in their hands, when it's raining.
If they were caught in a freak shower, fair enough, but who, other than the biggest clot in clot town, looks at it pissing down outside and thinks "I need to take this stuff back to the library, I won't bother putting it in a bag or trying in any way to keep it from getting rained on because I'm sure the library service have strange, magical devices that defy the laws of physics to remove the water from books and return them to the pristine state they were in when I borrowed them."
Clots.
If they were caught in a freak shower, fair enough, but who, other than the biggest clot in clot town, looks at it pissing down outside and thinks "I need to take this stuff back to the library, I won't bother putting it in a bag or trying in any way to keep it from getting rained on because I'm sure the library service have strange, magical devices that defy the laws of physics to remove the water from books and return them to the pristine state they were in when I borrowed them."
Clots.