Shankar talks about the ultimate understanding;
The moment you understand or the understanding happens to man, that he neither talks nor speaks nor does - and all three happen to him as an optical and auditory illusion of light and sound - he will be relaxed in life, he will be alive in life, he will not have to worry about what will happen in life, because life happens to him whether he likes it or not. He simply enjoys the life as a witnesser - witnesser means “he who witnesses life happening”, “he who witnesses and understands that life makes life happen and it is not man who makes life happen, least of all through his mind.
Whatever man believes happens in life, he beliefs it, it is just a belief to him, but not an understanding. If he understands life, he will realize, nothing happens in life. Life is just a movement of color, light and sound, forms and shapes. An action is an optical illusion, and an auditory illusion in the mind. But man is convinced of an action as a reality. Man needs to understand, that in life neither is time existent nor is anything physically real. There is not anything such as substance in life. Everything, which is known, is not of any substance or reality in life. It is just existent as a thought in his mind. Such is the intelligence of life.