A child is born means the mind is born. Mind is born means the universe is born. universe is born means duality is born. The duality is born means ignorance is born. Ignorance is born means the illusion is born.

As soon as word "mind" is uttered people think “the mind of an individual", whereas the mind is in the form of universe and universe  appears  as a whole waking or dream[duality]  experience and disappears as deep sleep[non-duality] . The body, ego, world are within the mind or universe or waking.  Thus individual and individual experiences are happenings within the mind or universe or waking experience. 

 The witness means "that to which anything appears.” This is an important and vital difference. The mind appears to the witness, which is the formless soul. The soul is also the substance of the mind.  

Mirage or illusion means which appears to be reality but by close examination one becomes the unreal nature of the mind, and becomes aware of the substance from which it is created of.

There is always confusion and there is no clarity about truth when one considers the ego [I] as self. Therefore, the self cannot be the 'I' or 'I AM, because on the base of soul, which is the true self there is no confusion and always clarity. 

When the mind appears all confusion and doubts arise and when mind disappears all will the doubts and confusion will vanish.  Then what is that is aware of the appearance disappearance of the mind. The physical existence [man + universe] is limited to mind, and it is mind.  Therefore, mind is limited to the physical existence.   

One cannot make the mind clear; without understanding the formless substance from which the mind is made.  The nature of the mind is diversity. Thus understanding the mind is necessary to understand and assimilate the ultimate truth or Brahman. 

Mind is mere illusion. What is mind will remain unclear if one never verifies the facts about the mind.  Without verifying the fact about the mind one keeps experiencing the duality as reality. When the illusion is taken as reality all the judgements will be based on the physical self, thus all conclusions will be based on the intellectual speculations; therefore one will not be able to understand and assimilate the ultimate truth.  

Only when one investigates the mind through deeper self-search self or soul  will be able to transcend the mind and come out of it, clarity will happen to him. He can be clear, about the facts of the mind. There is no such a thing as a mind or universe or waking  in the realm of truth; never has been and never will be. Mind means the illusion, in which the whole universe with all its contents exists. When there is no mind there is no illusion. Consciously becoming aware of the illusory nature of the mind in midst of illusion is wisdom. 

Try to understand the structure of the mind; the mind contains the whole universe. All individual experiences of thoughts, feeling, perception, mental formation are happenings within the mind, which appears and disappears as waking or dream.   A continuous process of thought, a continuous procession of thoughts -- associated, non-associated, relevant, and irrelevant -- many multi-dimensional impressions gathered from everywhere are belongs to the individual who perceives the world within the mind.  The birth, life, death and the world exit within the mind or universe  or waking and   their reality is limited to mind or universe or waking . The nature of the mind is impermanence because it is bound by form, time and space.

A child is born means the mind is born.  Mind is born means the universe  is born.  Universe  is born means duality is born. The duality is born means ignorance is born. Ignorance is born means the illusion is born. In illusion man thinks he is and individual separate from the world and world existed prior to him and he is born in it. Until this conviction is form it becomes difficult to accept the birth, life, death and the world as illusion. Therefore, it is necessary to know and realize the fact that, the self is not physical but the self is formless.  Therefore, the base of reasoning faculty has to be rectified from form to formless to realize the physical existence [man + world] is mere illusion. 

A child is clear because the ego is not formed. The moment ego appears, the unclarity, the confusion, enters. A child is clear, clarity but he will have to gather knowledge, information, culture, religion, and conditioning necessary, useful to the practical  life within the practical world. He will have to gather many things from everywhere, from many sources -- opposite, contradictory sources. From many sources he will gather. Then the he becomes store house of hotchpotch knowledge. And because of so many diverse knowledge, doubts and confusion is bound to be there. And whatsoever he gather, nothing is certain, because knowledge based on the ego is always a growing affair. Therefore, there is need to acquire Self-Knowledge to get rid of accumulated dross.  

Only through deeper self -search  one becomes aware of the fact that ,the self is not physical but it is formless. When the self is formless, then there is no doubt is left that the three states are mere illusion. Whatever prevails without the three states is the formless substance and witness of the three states, which is consciousness. Thus whether one accepts this truth or not he and his world exists as reality because of   consciousness.