Story via librarian Roz Warren.
Even though librarians like Warren have to deal with these characters, they also have to also maintain their cool. She suggests that she might write a book with survival tips someday, and she already has title ideas:
Because we librarians are helpful and courteous by nature, we refrain from telling these folks off. Or telling them to get the hell out of our library. Instead, we smile and do what we can to help them. Which, given what we’re dealing with, calls for its own special guide book. “When Difficult Patrons Happen to Good Librarians.” Or “Impossible People For Dummies.” Some day I might just write that book.