When you think, you are constantly making impressions on your subconscious mind. The heavier the impression, the more likely it will become your reality. The reason for this is that the subconscious mind doesn't know whether these impressions are real, or if they are not. So it adjusts your outer reality to match the impressions that are most dominantly being imprinted onto your mind. This process is called the imprinting process. You must watch what you are printing onto your subconscious all day long. You must be vigilant at all costs. Thoughts are things and will come to life if left unattended. Ask yourself, do I want this thought to be my reality? If you don't, simply become aware of the thought. Your awareness will stop the thought from being imprinted onto the subconscious.