My rational side says maybe you requested it a couple of months ago and it was set aside for you right away but then mislaid or something for all that time until some librarian found it and went, oh! I wonder if she still even WANTS this.
My less-rational side is thinking "mind-reading library fairy."
PS There IS a library elf. www.libraryelf.com. He saves me probably a hundred dollars a year in fines. ;)