What powerful movie changed your views on something important in life?

I often look at movies as entertainment, even serious ones. After all, they are not real life. But I've found that my views about many things have nevertheless changed because of some particularly powerful films. I am not saying my views changed necessarily for better.

This is going to sound dumb but after I saw The Godfather, that is the only thing I imagined every time someone spoke of mafia. Perhaps this is going to sound even dumber, but after I saw the animated feature Up, I suddenly realized old people were real people. That they were children once, that they once had big dreams, and that we sometimes ignore or mistreat them because we stereotype them.

Any other movies that you found changed your views about certain people or things?