From the Prologue:

When I started rereading children’s books, when I re-entered the lives in particular of favorite heroines, I found myself yearning to travel to the settings of those books.  It was as if the tourist sites that had sprung up might be living manifestations of stories that I once loved, of stories that had once themselves seemed like physical locations, places to which I could escape. They were, for me, as real as real life. As with my original impulse to reread books, maybe my initial motivation for embarking on these travels had something to do with nostalgia.  Maybe I was seeking to make literal the metaphorical experience of being lost in stories, of meeting again characters who had seemed three-dimensional, flesh and blood, like old, good friends, like a part of me.