To understand what is out there you have to take into account what is inside of you, the means by which we perceive the world and bring meaning and coherency to our experience. Essential to the process of determining what we know is the understanding of how we know, that is, learning to differentiate between conjecture and conclusion, beliefs and knowledge, dreams and consciousness, imagination and reality.
Many people have been taught to believe that knowledge is simply the accumulation of facts. But facts are of little use until they have been related to the self-evident of personal experience. Nature has provided us with the tools to conceive the nature of the heavens, but we must first learn how to use them, to relate what we think to what we know, to organise our thoughts conceptually into units of thought that we can grasp and retain bringing the heavens down to earth and within our intellectual reach.