Fantasy and Reality

It makes sense that we can indulge ourselves in fantasy.  After all, the ability to think abstractly, that is, to conjure alternate realities that share some essential qualities to our current state, is fundamental to survival.  We're very good at asking the question: What would happen if?  If that tiger jumped there?  If I could distract him with some steak?  If we cooperated?  If not?  Those that cooperated in our evolutionary history seemed to have survived much better than others, though we can't rule out free-riders completely, even though we don't like them.  Anyway, the point is this: it is very easy to imagine a reality that so closely mimics current reality that we convince ourselves that it is the current reality and we believe in it as if it were real.  But it isn't.  But our belief is sincere, and is often the difference between living and dying.  If I'm convinced of a danger, x, and my conviction is exaggerated 10% over reality, then I will suffer some opportunity cost in my caution, true--I could have been doing something else besides spending my time/energy on my inflated worry.  However, as compared to someone that underestimated the danger by 10%, I win, in that I'm not maimed or dead.  The balance, you're mind is probably screaming at you, is to find a way to maximize energy output on useful goals, or, stated more accurately, to minimize the extent to which we frivolously worry or expend useless energy.  And that's where modern life comes in.  We've automated a lot of our survival, made it more efficient (think of your next food source), so we have more time to indulge.  We have more time to be preoccupied with our fantasy, with unreality and it poses less risk than previously [in human history, on average].  That's pretty remarkable.  It allows great reward and great risk.