What book, other than the Bible, has had the greatest impact on your life? Why? Looking back I would say that "The Wizard of Oz" had the greatest impact on my life as it is the book that began my love of reading. I was in the 3rd grade. My mother realized how much I liked the book. She went to a local college and borrowed all the Oz books they had in their children's collection, in the Library Science Department, and brought them home for me to read.