Indeed, 'Lean on Me' is based on fact. It centers around Joe Clark and his mission to bring discipline and success to a struggling school. His leadership and unwavering commitment are the core of the story.
One main theme is transformation. The school goes from being a place of chaos to one of hope and progress. Another is leadership, as the principal shows great leadership skills. And also there's the theme of community, as everyone in the school has to work together.