Written and Narrated and by Robert Jennings, InnerSelf.com
Nothing is as simple or as complicated as it seems -- including this tidbit. - Robert Jennings
If left to whim, we will mostly be driven by our biases and we have lots of them. One that most of us have is an optimism bias. Some estimates are that roughly 70-80% of people have this bias. There is a pessimism bias as well. While I am convinced that it is much better to be optimistic than pessimistic, we must be aware of the downside to both biases.
A pessimism bias is primarily driven by fear and that was predominant in our early evolution. But gradually, this pessimism bias was replaced by optimism as our lives improved. This idea of progress is perhaps best captured by the concept of "one step forward and two steps back".