Acharya Prashant explains that the mind is the totality of everything you perceive around you—the world, activities, sounds, sights, memories, desires, people, and things. When these appear externally, they are called the world (sansar), and when this world is reflected within, it is called the mind (mann). The mind and the world are essentially two sides of the same coin. The mind is the field where the ego (aham), or the false 'I', operates. This ego constantly changes its identity, much like characters in a dream, identifying as a lion, a rabbit, a lawyer, or a son. This continuous shifting and the conflict between these false identities are the root cause of suffering. The Self (Atma) is the true 'I', which is synonymous with the word 'main' (I). The journey to knowing the Self is a process of investigating and discarding all these false identities of the ego. This method of negation is what the Upanishads call 'Neti-Neti' (not this, not this). When all false identifications are removed, what remains is the singular, true Self, which is the same for everyone. Unlike our bodies and minds, which are different, the Atma is one. The suffering caused by living with false identities is the primary motivation for this spiritual inquiry. Liberation (mukti) is not about a future life but freedom from the suffering experienced in the present moment. It is freedom from the hell of the now, not from a future birth. The concept of rebirth is the mind continuously taking on new forms. The quality of one's actions (karma) is important because it has an immediate impact on the present and shapes the future moments of this life. A wrong decision leads to immediate suffering, while a right one brings joy. Consciousness (chetna) is the ability to cognize and say 'I', and it is always associated with the body. The body's purpose is to serve as a vehicle for the evolution of consciousness. Death occurs when the body is no longer fit for this purpose, and consciousness is extinguished like a flame; nothing actually 'leaves' the body. The speaker also distinguishes between spirituality and science. Mysticism, he states, means that the ultimate Truth (Atma) is unknowable, whereas everything else in the material and mental world is knowable and falls within the domain of science. He cautions against two errors: superstition, which claims knowable things are unknowable, and materialism, which claims nothing is unknowable. The spiritual path involves investigating the knower (the ego) until it dissolves, leading to liberation from all falsehoods.