We need to find the balance between using our mind to create our reality and living in denial. The first requires that we assess a situation with objectivity and take steps to transform it to our liking; the second causes us to ignore reality and invariably be struck by disappointment.
Uncertainty is a description of reality, and yet, we have expectations about most everything we do. We would be happier and healthier if we dealt with life and the world the way it is rather than some fantasy we have about it. We can dream of a better world and take steps to participate in its transformation, but we cannot expect our reality to change until we take steps to change ourselves and our behaviors.
The key is to be positive in your outlook, do not hide behind your fear, face reality, see it as it is, it will allow you to be objective and take appropriate action. Wishes are not enough. For them to become reality, they need to be propelled by the strength of your desire and the power of your actions.