Pay It Forward (2000) on Netflix

A school social studies assignment leads to social changes that spread from city-to-city. Assigned to come up with some idea that will improve mankind, a young boy decides that if he can do three good deeds for someone and they in turn can "pay it forward" and so forth, positive changes can occur. What appears to initially be a failure, is indeed a success that is not immediately known but is traced backwards by a reporter who is a benefactor. The initial recipients of the boy are a drug addict, his badly scarred school teacher, and a classmate who is constantly bullied by his peers. While physically and mentally scarred by past events, the teacher is not the only one bearing scars. The young boy fears his mother's fate, particularly at his brutal, alcoholic father's hands. The mother also bears scars from her childhood with a homeless, alcoholic mother.