When I was a little kid, in first and second grade or so, we had "Library" as a lesson once a week, where we'd go to the library and have the librarian show us things or read us books or whatever.
At the end, we got to check out books if we wanted, but no more than one per week in first grade and two per week in second grade. (I forgot how it went up after that.)
I remember feeling awfully frustrated because I got through my books a lot faster than one or two a week, but we weren't allowed to check out any more books until next week.
Oh, and while we were in Junior School, we weren't allowed to check out any books from the Middle/Senior School combined library. (The other way around was allowed, though.)
P.S. New icon, ganked from chrissie_t; original picture from the "Pearls before Swine" comic.