Libraries are some of my favorite places. I've worked in two of them.
Growing up, the library in my town had a youth card. When you were twelve, you could get a card to access the whole collection. But for a long time after I turned twelve, I wondered--why would anybody want to access the adult books? There was nothing to read there--at least, nothing enjoyable. Obviously (to me), all the best stuff was in the children's room.
I felt nostalgic when I read this article in AnnArbor.com today:
University of Michigan Library to bid farewell to card catalogs