Pay It Forward (Spoiler Alert)

I watched Pay It Forward for a little bit today. The theme of this movie is that anyone can make a difference, whether you're a child, or an adult. You never know that if what you do or what you say effects others. It has to be one of my favorite movies of all time. I love the concept that a seventh-grader can come up with an idea that changes the world for the better. I think some of the best ideas come from or are inspired by the purity of children. The only aspect of this movie that I just can't understand is why Trevor has to die in the end. Maybe it's supposed to represent the loss of the purity of children? I just don't see how this reflects the overall message of the picture.