Living in the present means living in the myth and experiencing the myth as reality. The past, present and future is based on the waking entity or ego which is the false self within the false experience(waking). There is neither past nor present, nor future in reality. Thus the seeker of truth has to realize the fact that, the past, present and future is part and parcel of the illusion, which comes and goes as waking or dream. The one which is aware of the coming and going of the three states is apart and eternal. Thus, it is necessary to overcome the myth that we must live in the present.
Living in the past and living in the present and living in future means living in duality. Duality is mere illusion on the standpoint of the true self, which is the soul.
There is a necessary to understand "what is mind ?', and then only it is possible to assimilate the self-knowledge or Brahma Gnana . If one limits the mind to the physical entity then he will remain believing in the idea that mind is bundle of thoughts. This mind is bundle of thoughts idea keeps one in the grip of duality and makes one experience duality as reality.
The thoughts are part of the myth. The thoughts, memory and experience have no relevance in pursuit of truth, because the individuality itself is myth. Thus, individual experiences’ happening within the waking is as real as dream. The waking is parallel dream and dream is parallel waking experience.
Thus, the truth is not based on individuality but the totality of the three states, which appear and disappear in succession. Thus the intellectuality, which is based on the physicality, will yield only the understanding based on the ego, which is the false self. The non-dual wisdom will not dawn by studying the scriptures, or intellectual arguments but it will dawn only indulge in deeper inquiry, analysis and reasoning.
The true self is not the waking entity or ego. Basing one-self on the ego and trying to understand and assimilate the self-knowledge is impossibility. The true self is the soul, which is within the three states but it is apart from the three states. It is within the three states as their formless substance and it is apart from the three states as their formless witness. It is apart because it is not an entity or identity within the three states. This formless witness has to be grasped mentally by constant reflecting on the subject, which is formless soul and realize the fact that the true “Self” is not an individual. Thus, it is necessary to rectify the seeking base from form to formless to understand, assimilate and realize the non-dual truth.