Why had Jim decided to run off when he did?

Jim decided to run off when he did because he felt a strong desire for freedom and autonomy, which he believed he could only achieve by escaping his current situation. His longing for adventure and a life outside of societal constraints drove him to take the risk. Additionally, he was motivated by the hope of finding a better life and the opportunity to pursue his dreams without oppression. Ultimately, Jim's decision was a reflection of his yearning for self-determination.