What events lead up to tom running away?

Tom runs away primarily due to his desire for freedom and adventure, feeling suffocated by the constraints of his life in St. Petersburg. The oppressive nature of his Aunt Polly's strict upbringing, combined with the teasing he endures from his peers, drives him to seek an escape. Additionally, his fascination with the stories of pirates and outlaws fuels his romanticized vision of life away from home. Ultimately, the combination of these factors culminates in his decision to leave in search of independence and excitement.