One way that a flashback reveals an aspect of Okonkwo's life is in Chapter One as the history of Okonkwo's father is revealed.
When he was young, Unoka, the grown up was a failure. He was poor...People laughed at him because he was a loafer and they swore to never lend him more money because he never paid back.
As a result of his father's indolence and lack of character, Okonkwo aspires to define himself through his industry and strength. Because he has had to "fend for himself" as a youth, Okonkwo constantly strives to appear as a brave warrior; consequently, even when he is told to not interfere, Okonkwo participates in Ikemefuna's death, even though he is like a son to him; for, he does not wish to seem effeminate and weak like his father.
Okonkwo is truly haunted by the memory of his father because he is "possessed by fear of his father's contemptible life and shameful death." When he observes his own son, he fears that Nwoye is being lazy and he sins in Chapter 4 by breaking the Week of Peace as he beats his son. In addition, the more he achieves, the less he enjoys his success because his constant fear of failure drives him to other actions, some of which are not wise. Also, his focus on his single life distances Okonkwo from communal life. As a result, he becomes estranged from his oldest son, and he loses support from his clansmen when he seeks to unify them with him in rebellion.