Self realisation is experiential, and not intellectual. That's why the intellect couldn't grasp it, because you can only grasp an object, or grasp a concept objectively. An experience is realised. I am not this 90kg body, I the consciousness. When a bell is rung, the sound is being manifested in the consciousness, therefore the mind through it's senses (using various sense organs) is experiencing it. But experiencing the sound in what? The consciousness. Was this understanding intellectual? No Had it been intellectual, it would have been interpreted as: Oh an object was hit to a metal which caused vibrations, and those vibrations due to the intensity of the impact then started to resonate and slowly spread and reach the ears which then vibrated and created the sense of hearing. But, instead I experienced it, it emmerged in me, and it settled in me. What was there all this while? The supreme silence. The true self, the ultimate reality, consciousness.