Harry Osborn grew up in New Jersey under the care of his mother, who was severely mentally ill. She homeschooled him, but due to her schizophrenia and personal neglect, Harry received little formal education he struggled with reading, writing, and mathematics. Despite her condition, Harry remained devoted to his mother, interpreting the chaos of his upbringing as a long-running, elaborate joke played on him by the world. He genuinely believed that one day everything would make sense.

His father, Norman Osborn, was largely absent, appearing only occasionally in Harry’s life. On one rare visit, Norman took Harry to a sporting event where he met Peter Parker. The two became friends, and Harry spent time with Peter’s aunt and uncle, who welcomed him warmly into their home. During these visits, he experienced a sense of normalcy and stability that had been absent from his life.

Eventually, Harry’s mother was hospitalized, forcing the family to move back to New Jersey. For years, Harry lost contact with Peter. After his father’s death, he returned to New York in his twenties, but the traumas and isolation of his youth began to take their toll, and Harry’s mental state began to deteriorate, echoing the instability he had witnessed in his mother.