Acharya Prashant explains the concept of subtlety by using the analogy of a faint fragrance or the twinkling of stars. He notes that if one's senses are constantly bombarded by gross stimuli—such as bright lights, loud noises, or pungent smells—one loses the capacity to perceive delicate and subtle experiences. This grossness dominates the senses, leading to a state where the subtle remains unperceived. He emphasizes that even beyond physical subtlety, there are experiences like a thirst that water cannot quench or a light that the eyes cannot see, which are only accessible when one reduces the dominance of the gross in their life. He further elaborates that the Truth is extremely subtle, whereas the world is gross. To begin perceiving the subtle, one must practice constant vigilance over their daily routine. He compares this to a police checkpoint or a toll booth where every vehicle is stopped and inspected. Similarly, every thought and action must be scrutinized before being allowed to pass. One must question the origin of their thoughts, asking whether they truly belong to themselves or are merely reflections of external influences like family, media, or corporate culture. Acharya Prashant warns against absent-mindedness, which allows external garbage to enter the mind. This creates a vicious cycle where the presence of such influences further increases one's lack of awareness. To break this cycle, one must remain alert twenty-four hours a day, questioning every impulse and inspiration. For those who find it difficult to observe their thoughts directly, he suggests starting by observing their actions and physical expressions. By honestly examining one's behavior and even one's own face in the mirror, one can begin to uncover the reality of their internal state.