"A WISH IS A DECLARATION OF THE MOUTH THAT THE MIND KNOWS IS A LIE"
Your beliefs have a profound effect on how you perceive what's happening, because they act like filters. They let some things through and block out others, based on how compatible the information is with what is already there.
It works much like the filter on a camera, designed to give you the picture you want rather than the picture that is. Similarly, the subconscious mind that receives the perception is much like the film. It accepts completely, without question, everything it receives as true, and spits out your fabricated picture of life in all its glory, just as if it were real. And then it uses that as the basis for judging the reality of the next perception.
THE SOLE PURPOSE OF THE RATIONAL MIND IS SURVIVAL OF WHAT IT THINKS IS SO (YOUR PREMISE).