My first week of college when I was 18 and horribly homesick (home was a dreadful 168960 feet away from me) I was wandering through the library and found a sea-foam green hardcover book whose title I can't recall. It was text heavy but still had illustrations and it was for people who were trying to create spaces for preschool-aged children. The book drew from Child Psychology and suggested that spaces for children ought to be built for minds that like to discover. Children, it said, love to find things. They love to explore. They love small places where they can feel safe and hidden. That book felt like a safe secret world to me at that time when I was grieving childhood and I returned to it again and again when I felt sad, alone or bored.  12 years later I still think about that book, but I can't find it- even though I'm typically very good at finding nameless things online. It drives me crazy.