Personal Belief Vs. Reality

Who's really in control of what you do? Who dictates what one thinks or believes. One's feelings toward or against something is personal and intimate. But the environment of a person also dictates a lot. The environment changes so humans have to change with it, including their beliefs. So as one goes through life they are constantly in a battle of personal belief vs. reality. Reality itself can be a dark place with lots of unhappy facts that one can't change, so maybe that's why we hold beliefs so close to our heart.