Acharya Prashant explains that our lives are divided between the external world of events and the internal world of thoughts and emotions. To attain the state of being a witness, one must practice indifference toward trivial external stimuli and internal impulses. He emphasizes that witnessing is not a complex task but rather the act of remaining immersed in what is truly significant while ignoring the rest. This state of absorption, where one is neither welcoming nor bidding farewell to worldly events, is compared to a fish immersed in the ocean, unaffected by a fair on the mountains. The essence of being a witness is to be so engrossed in the essential that the non-essential ceases to distract.