TFA: Chapter 16

In chapter sixteen, Nwoye leaves Okonwo's household and joins the Christians. When asked by Okonwo's friend Obierika, "How is your father?" Nwoye answers, "I don't know. He is not my father." The book mentions that Nwoye answers this question unhappily. Why do you suppose Nwoye is not proud of breaking his tie with his father? After years and years of living together, Okonwo and Nwoye have grown further and further apart. What is it do you think that Nwoye wants from his father? Affection? Acceptance? Okonwo gives everything Nwoye needs-food, shelter, work-and plans to give all his wealth to him when he dies. Why is it that Nwoye is dissatisfied with his father enough to disassociate completely with him?