It is difficult to imagine not feeling at least some sympathy for the young narrator of This Boy's Life, a vibrant protagonist who refuses to surrender his belief in himself and his future despite a turbulent adolescence.
Jack relies on his imagination to escape from the grim circumstances of his childhood, which is riddled with domestic violence, alcohol abuse, criminal activity, and emotional neglect. As a coping mechanism, Jack pays little attention to how he is perceived and instead imagines himself wherever he wants to be, free of the restraints placed on him in real life. Jack's imagination is what drives him to overcome the adversity he must endure at home, especially at the hands of Dwight. Sometimes, however, Jack is overcome by the power of his fantasies and is convinced that they are even more real than reality. For example, when Jack forges letters of recommendation from his teachers, he is fully aware that he is writing lies, but to him they seem more real than the facts, unveiling the core of virtuosity and intellect that Jack believes are inside of him. Whichever school Jack attends, he has a knack for befriending the school's most notorious troublemakers. Jack possesses a strong sense of self and refuses to allow anyone else, especially Dwight, to define him, but he cannot help but be influenced by his delinquent friends to drink, steal, and generally wreak havoc.
At heart, Jack remains a kind person, and is especially caring and compassionate toward his mother. Jack's relationship with his mother is complicated and intimate, and it is not unusual for him to sometimes act as her parent, comforting her when she is sad and offering her guidance. In this way, Jack is more mature than most boys of his age, and feels he must accept responsibility even for situations and events that he could not have controlled, such as his father's abandonment of the family. This sense of responsibility and duty manifests itself in Jack as a deep sense of guilt, which plagues him throughout his youth. As a young boy especially, Jack feels inadequate and unworthy of any good fortune that presents itself to him. However, as he grows older, Jack realizes that he deserves more than the meager attention and care he is given.
As a mother, Rosemary is unconventional, wanting to travel and explore instead of bake cookies and make babies. It is clear that she loves her son very much, but her well-meaning decisions can prove destructive, such as her marrying Dwight for the sake of providing Jack with a stable home life. In her attempts to assume a conventional, family-oriented lifestyle, Rosemary betrays herself and suffers for it, even though it is never her intention to inflict harm on Jack or on herself.
Rosemary's temper is remarkably mild, much like Jack's. Even when Jack has caused terrible trouble or shamed himself, such as when he steals from the Welch's farm, Rosemary cannot bear the thought of striking or even verbally reprimanding him. Rosemary's restraint is the direct result of her own abusive childhood, as she is deeply scarred by the violence and cruelty she has suffered at the hands of her father. Although Rosemary makes a conscious effort not to treat her children like her father did, she is attracted to men who use violence to assert their authority and power. Rosemary is fiercely independent, but whenever she has garnered sufficient courage, strength, and money to leave one of bully, she moves on to yet another.
Like Jack, Rosemary never loses faith that her situation will improve, however tragic her circumstances. She remains confident that whatever hardship she is enduring will eventually pass.
Dwight is unmistakably the antagonist of the memoir, a villain who steals Jack's happy childhood right out from underneath him. Dwight is cruel, a monster whose only motivation is to degrade and defile everyone he can. The worst of Dwight's brutality is directed at Jack, who is rendered helpless by Dwight's unflinching adult authority.
Dwight mercilessly berates Jack for his every move and, at his worst, uses physical force to make his power known. Dwight derives satisfaction from exercising his power over other people, primarily Jack and Rosemary, and needs to belittle and victimize others to reassure himself that he is important. Dwight is also exceedingly deceptive and dishonest, either making various promises he cannot keep, or simply lying outright, relishing his self-serving underhandedness. This deception is best exemplified when Dwight steals Jack and Rosemary's hard-earned wages, spending the money on himself after he has assured them both that he is depositing it into their respective bank accounts.