I totally understand how that 13 year old felt. Your mom probably thought that you could learn something new because you are growing up. She probably did not even give the book a second thought. If she could only know how the indelible mark this book left on you. However there is no need - you older self understands the gesture.
I can understand the adult feelings - being overcomed with emotion for the thoughtful gift. Even clink of the mobile will make you happy - every glimpse will make you smile.