I find the question "What book changed your life?" hard to answer.
1. I want to say Readers' Digest Condensed Books. I say this not because I read them, but I witnessed my mother and her friends in rural west Texas reading them. In the 1960s subscribers to RDCBs got four volumes per year, each holding three to five titles by contemporary authors. Mom read them, criticized them if they did not meet her standards, and loaned them to nonsubscribers. From RDCBs I got the notion that there was a book world somewhere far away.
2. I also want to say John Audubon, Boy Naturalist by Miriam Evangiline Mason. In fourth grade I read the entire book the day I checked it out from the library. I do not remember ever being so taken with a book before that day.
3. Hannah Coulter by Wendell Berry is a book that I admire highly. I read it just three years ago. Knowing that such good stories are available, I never have to read anything inferior again.
4. I am still seeking the book that changes my life. It is still out there.
5. As several of the writers in The Book That Changed My Life say, every book changes me.