Restart by Gordon Korman

A middle school bully wakes up in a hospital with amnesia, unable to remember his past actions or identity. As he returns to school, he is given a chance to reinvent himself and discovers the impact of his previous behavior on his peers. Struggling between the remnants of his old self and the opportunity to forge a new path, he navigates friendships, rivalries, and the complexities of adolescence, ultimately learning the power of redemption and the importance of empathy.