Existence is mysterious. Because it is mysterious it can never be known. We are not aware of the mysterious nature of existence. We are part of existence. The part cannot know the whole but it can participate with the whole. But we do not know how to participate with the whole because we have private goals to achieve apart from that of existence. Though it is never possible to be separate from the existence, in the present state of our understanding we are feeling that existence is separate and contrary to us. How this state of affairs happened? We are a product of evolution and whatever we experience is stored in memory cells. When we function in the objective reality we face new challenges every moment and we are facing these challenges from the thought born out of dead past which results in incomplete action and the residue of incomplete action is experience. The summation of all such experiences is the ego and from that we are functioning both in objective reality and in the psychological realm. As far as objective reality is concerned such accumulation of information regarding the matter and acting from that memory is useful in science, technology, medicine etc. But we are using the same accumulative process in the psychological realm also creating many problems for ourselves.