Once Osho said how many millions of japa do you need to make before you realize 2 = 2 does not equal 5? In the largest sense, enlightenment in the Advaita and Buddhist traditions, has to do with loss of ignorance or miscomprehensions of who and what we are. That is, we lose concepts, desires and our "past." We need to see anew.
Then the trick becomes, "How do we do that?" One can do it by self-inquiry, looking into our inner emptiness for the entity we suppose is us, and not finding it, realize we are that emptiness, that space.
But no, there is another step. We realize that even that space we see, is still seen, it is still an object to "ME," who I suddenly discover is beyond all of this phenomenality.
Nisargdatta invented a way to awakening only loosely based on his own teacher's teachings, and that was to find the I, and the Amness surrounding that I, meditate on that bundle, love that bundle, and thereby please the I-Am so that it releases its secrets to you.
It took him 9 months to locate the I Am and another 2 + years before it released all of its teachings to him.
Then when release comes, and you see you are the emptiness that precedes even the emptiness we perceive, we are the Great Void itself, each and every one of us, we clearly perceive that no effort that had been made in the illusion of existence could have possibly released us, because we ARE prior to existence and the illusion. Yet, paradoxically enough, that effort was needed for the apparently imprisoning illusion to dissipate. A paradox indeed. But what happiness and peace we feel once released.
But this initial release is only the beginning. You are now awake, but that only means now the lights are on, the pathway forward is marked and lighted. The enlightenment continuously deepens. Nisargadatta near the end of his life disavowed his teachings as presented in "I Am That" written in the 1970s. The Nisargadatta of 1980 changed and finally transcended consciousness itself. However, many, many who read Maharaj only see his teachings of I Am, of oneness consciousness, and make him a titular founder of the neo Advaitin school.