When you work with a good actor, there is this natural rapport and chemistry that develops over time. That chemistry helps your characters come alive and makes the story of the film that much more convincing.
Humans know when it's not a good story. Unless you do this for a living, you may not know exactly why you don't like a story, but you can't fool an audience ever. They know when you have it and they know when you don't.
From earliest times, humans - explorers and thinkers - have wanted to figure out the shape of their world. Forever, the way we've done that is through storytelling. It is difficult to let the truth get in the way of a good story.