I am reading Story by Robert McKee (because the structure of stories interests me). There is a profound passage which totally resonates with everything we discuss here.
Every human being acts, from one moment to the next, knowingly or unknowingly, on his sense of probability, on what he expects, in all likelihood, to happen when he takes an action. We all walk this earth thinking, or at least hoping, that we understand ourselves, our intimates, society, and the world. We behave according to what we believe to be the truth of ourselves, the people around us, and the environment. But this truth we cannot know absolutely. It’s what we believe to be true.
We also believe we’re free to make any decision whatsoever to take any action whatsoever. But every choice and action we make and take, spontaneous or deliberate, is rooted in the sum total of our experience, in what has happened to us in actuality, imagination, or dream to that moment. We then choose to act based on what this gathering of life tells us will be the probable reaction from our world. It is only then, when we take action, that we discover necessity.
Necessity is absolute truth. Necessity is what in fact happens when we act. This truth is known — and can only be known — when we take action into the depth and breadth of our world and have its reaction. This reaction is the truth of our existence at that precise moment, no matter what we believed the moment before. Necessity is what must and does actually happen, as opposed to probability, which is what we hope or expect to happen.
As in life, so in fiction.
In other words, the best we can do is make a prediction. We will not, we cannot, know for certain what will actually happen until it does. The choice we make in that moment to either learn from this experience, or disregard it, is what decides the course from that point.
We are all protagonists in our own lives.