When a family of four spend a good hour or so browsing our library's selection, leisurely choosing the books they want, having been informed several times that we're closing at X time, which is fast approaching, and then they come up to the desk at X minus thirty seconds and mention that, oh yeah, they don't have library cards and have to be signed up. Then after that takes them several minutes past closing time they want to go downstairs to sign the kids up for the summer reading program, which takes a few more minutes. And then when a departing coworker tries to herd them out the downstairs doorway they decide that, no, they'd really like to go out the upstairs door. So they walk very slowly up the stairs and out the front door, which deposits them about 20 feet from where the downstairs doorway would have put them. And then, of course, they start walking away towards the downstairs exit. Which means that at the end there they wasted their own time as well as mine.
Very nice people, every one of them, but holy crap did they annoy the snot out of me. It's like they were playing a game and they got extra points for the longer they got to stay in the building after closing. There actually are people who seem to get their jollies keeping us past closing, but these folks were just terminally clueless. They still managed to delay us later than anyone has in years, though, from a combination of us trying to give good customer service and me constantly thinking "Surely they'll leave now. Right?"
When I followed them up the stairs at the end, the mother kept sneaking glances at me. I think she thought I was rude for following them, but I had to make sure they actually exited the stinkin' building before I could start closing everything down. I just know they're going to think staying late is normal the next time they come in.