Most of the time, 'Sam I Am' is not a true story. It might be a made-up tale with elements designed to engage and amuse the audience, rather than representing real events.
Since I'm not sure which novel 'I Am Sam' is based on precisely, I can't list specific similarities. But generally, if a movie is based on a novel, they might share the main characters' traits, the overall story arc, and the central themes.
The movie 'I Am Sam' takes cues from real-world circumstances involving people facing similar challenges. However, it's not a strict retelling of an actual event. The filmmakers combined various real elements and creative imagination to create the story on screen.