Mind is universe. The mind or universe is only an object to the subject. Mind means subject and object together. The self is only the subject without the object. The "Who am I?" quest naturally troubles people first because everyone is most interested in himself before he gets interested in the world ,which confronts him.
The “Who am I?” inquiry is useful as a first stage to show the illusoriness of ego and thus help seeker to realize ego is false self. This prepares him to consider the higher question: What is the universe, the truth about which cannot be learnt by those attached to their ego, with its prejudices against idealism, etc.
If one asks why there are so many different creatures and things in the universe one may regard them as teachers, there are lessons to be learnt from them by using reason. Why did God produce all these varied forms? It is so that the ignorant people may study them and get wisdom
One has to study the whole world, which confronts him. People think that their duty to the world to remove their personal sufferings thus their belief system becomes important to them. Seekers of truth want to get rid of all their doubts and confusion to get freedom from duality.
A yogi, who goes on uttering “I am within everyone" or "I am Brahman" is merely repeating like a parrot words which he has read in the Upanishads or heard somewhere. It does not prove that he has realized Brahman/Ultimate truth. He will be unable to prove that everything is” I AM” if hold I AM as self.