What are the motifs in A Man Named Dave: A Story of Triumph and Forgiveness by Dave Pelzer?

Self-worth is a reoccurring idea in the story. One may understand how, as a severely abused child, Pelzer feels worthless. He believes that his mother changes from a loving Mommy to the hateful Mother because of some unknown wrong committed by him. He strives everyday to be good enough to lure the Mommy back into his life. He feels guilty that the rest of his family suffers under the Mother because he feels it is his fault. He even takes responsibility for his father's departure from the family.