I could be wrong because I did this a while ago, but I believe I left the note in the Chronicles of Narnia. I have left notes in books before. They're usually about how great the book is or how I came to love this book and one time I just wrote a love letter to a reader. I like doing it, though sadly no one has ever answered me, because I'll my phone number on each note. But i guess it's understandable. If you found a book in a library would you answer? probably not.
I still enjoy it.
Until next time my friend