How Can a Story Take on a Life of Its Own?

When the rescue party arrived with food, some of them cast it aside and seemed to prefer the putrid human flesh that still remained. It shows how a story can take on a life of its own so fast and become far more than itself. Why do we often turn stories that are really just sad into stories where there is a sort of sensationalistic evil at the centre of it? And i think that we focus so much on on the bad things that they did to survive,. We don't think about the ways that they helped each other, they did everything they could before ray.