When Svetaketu came back to his home after receiving knowledge from the Gurukul, he became very proud of it. He came to his house and sat there arrogantly without even talking to his father. His father, Uddalaka, seeing this became worried. He thought what has happened to his son. Why is he not talking and sitting there arrogantly. Uddalaka approached his son Svetaketu and asked, 'Have you learned everything?" Svetaketu replied, "Yes, father." Uddalaka again asked him, "Have you learned about that One thing by knowing it you know everything?" Svetaketu was perplexed. His guru in the Gurukul never talked about that One thing. He had learned all the Vedas, Puranas, and Chandas but have not heard anywhere about this One thing. Svetaketu's arrogant and proud suddenly dropped and he humbly said, "No, father. I haven't heard anything like this before. What is this One thing you talking about?" Then starts the Chhandogya Upanishad. Can anything come out of nothing? Have you ever seen rain without clouds? Can being come out of Non-Being? Is this possible? It will be absurd even to think about it. If this is the case, then, is Being the cause of the Being? This is like asking is fire cause of fire? Is chair cause of chair? This is a meaningless question. So, the creation cannot come out of nothing or non-being. Creation (Being) cannot also be the cause of Being, since saying water is the cause of water makes no sense at all. If Being and Non-Being both are not the cause of this creation, then what is the cause? There is no cause AT ALL. Is creation really there as a solid objective reality? If there is no cause of this creation, then what exactly is it? The answer to this question is the crux of Advaita Vedanta. Before, understanding the term Advaita, we must observe closely the phenomenon of cause and effect relationship because the idea of creation solely depends on cause and effect relationship. Are cause and effect different? If they are different, cause is not really the cause of the effect. Then, are they same? If they are same, why do we even bother to denote it saying cause and effect? We are in a dilemma here ! We are caught in both ways. Hope you realize this One thing which is indescribable, which senses cannot perceive, which is beyond scientific investigation, which is beyond mind and intellect. However, there is a way to understand this One thing. This is the path of Advaita Vedanta. Om Shanti.