Acharya Prashant explains that we typically understand the world through materialism, believing that one physical substance (bhoot) originates from another, and we settle the matter there. He clarifies that 'bhoot' means a material or physical substance. When you attribute the origin of one substance to another, and the second to a third, this is called materialism. We apply this same logic to ourselves, concluding that we come from our parents, and we stop inquiring any further. We say that everything that exists has come from within the material world, but we never ask where the entire world itself came from. The speaker points out that we lack the mental energy and restless honesty to inquire further, and we are satisfied with cheap answers. We might trace our lineage back to a single-celled organism, but we never ask the crucial question: where did consciousness come from? Because we don't ask this, it is convenient for us to consider ourselves as merely the body and our parents as our sole creators. We never go beyond this superficial understanding. The substance that is the cause of all substances is called Parmatma (the Supreme Self). It cannot be an ordinary substance, because if it were, it would also have a cause behind it. Therefore, it is the ultimate and the first. It is that from which everything comes, but which itself comes from nothing. Its existence is necessary because if it does not exist, we cannot exist. The fact that we exist proves that it must exist. Spirituality is not about believing things; its purpose is to shatter our beliefs by making us ask the questions we don't normally ask. The ultimate cause must be non-physical and non-mental, beyond thought, form, and attributes (nirgun, nirakar). If it had attributes, it would also be part of the causal chain of the world. According to the Upanishads, this entire world is an extension of the mind. The point where the mind dissolves is the same point from where it begins. Where you have come from is where you have to go. In between, you are on a journey, which is the cause of all restlessness. This journey itself is a fabrication. Since we cannot accept that the journey is an illusion, the next best option is to learn how to undertake this journey with awareness. The Upanishads provide the discipline, method, and manners for this journey. To know how to live, one must first know who the one living is. The individual self (jeevatma), the ego, is the one who is searching and is restless. Liberation is the realization that this cycle of searching was an illusion. We are all seekers, and our desires are proof of this search. The fundamental mistake is seeking the infinite through finite objects and means.