I think you're correct in your assessment, but there's more to it. Specifically we must remember that evolution finds more useful solutions over time, but not n

I think you're correct in your assessment, but there's more to it. Specifically we must remember that evolution finds more useful solutions over time, but not necessarily the most useful solutions. A local minima of cost can be found while ignoring an even lower point of cost on the other side of a hill. It would be ridiculous to expect us to have found the most rational course of action in a given situation, even accounting for the mental costs you mentioned.