Obsessed by an imaginary ideal of normalcy, Rose initially responded to Charlie’s mental disability with denial. She insisted that her son was normal, and she developed a delusional theory that he was brilliant but was cursed by jealous neighborhood mothers. Her refusal to accept her son’s disability was demonstrated by her decision to name Charlie’s younger sister Norma because it sounds like “normal.” After Norma’s birth, Rose turned her full attention to Norma’s success and tried to ignore Charlie altogether. Signs of Charlie’s progression toward adulthood, especially his manifestations of sexuality, infuriated Rose. She demanded that Charlie be removed from her home. By denying his existence, she also denied what she perceived to be her failure as a mother.
When Charlie, now brilliant after his operation, visits an aged Rose near the end of the novel, her capacity for denial has grown into full-fledged dementia. She switches back and forth from recognizing Charlie to thinking he is a stranger, and back and forth from pride at his recent accomplishments to an irrational fear that he has come back to molest Norma. In her old age, Rose has been driven entirely mad by her overwhelming yet doomed desire to be what she perceives as normal.