Willie's mother is a brutal bully and her abuse of Willie has shaped his personality. Lacking self-esteem, Willie believes that he has no talents and no qualities that might make other people like him. When we first meet Willie, he still believes these things, because he has never known anything else—until he comes to Weirwold. As well as being emotionally abusive, Willie's mother is terrifying in her physical abuse of her son, going so far as to pack the thick leather belt that she beats him with in his things so that Tom can continue in the same vein. This is an indication that she genuinely believes that it is normal to use this kind of force on a child. Her abuse escalates into murder when she abandons baby Trudy in the cellar with Willie to starve to death.
A life marked by abuse creates a sense of trauma in Willie, which is illustrated through his constant wetting of the bed following both times that he comes back from his mother. Yet the author shows us that there are two different ways that one can deal with trauma. There is the way of Willie's mother, who we can infer has probably also been a victim of abuse herself. She becomes hardened from it, locked into patterns of violence that she then perpetuates against her children. This violence continues what is likely a long cycle of abuse. The other option, symbolized by Willie, is to learn from trauma and consciously choose something different—love, instead of hate. We see how the depth of trauma experienced has actually, by the end of the novel, helped Willie to become truly grateful to be alive.