Or in my case, a prediction machine that is more often wrong than right.
That is, even if your brain is only right some of the time, it matters more that the times it is right are important.
Constantly making small mistakes is the price to pay for successfully surviving when it matters.
That is why some people have brains that lie to them less then others, while others have brains that lie more. You will find different degrees of bias and delusion in the people you encounter.
What if atoms are not defined by deterministic rules? What if it's defined by probabilistic rules? Then are our brains bounded by the same probabilistic rules?
It seems that given that all brains are made of the same stuff as the universe, the question of free will is more of a physics question. What is the universe made of? And does this fundamental unit allow for free will?
A bias toward wrong predictions can be adaptive. If a wild animal comes across something that is 99% safe and 1% fatal, it could well be better off predicting doom and fleeing just in case.