This is such a good question and one that is difficult to pin down as far as what defines our knowledge that a book is going to become an all absorbing experience. But all I can say is that in the best books the language just flows endlessly and seemingly effortlessly like a River of silk, beneath your eyes and directly into your heart. You truly are experiencing a kind of out of body experience when you find a book you fully connect with— that rush I mention in my poem. What a gift it is to connect via a superbly written book with another human being you will never meet but whose mind and spirit touches yours.