Nachiketa, the Upanishad will tell us later on, Shravana, Yapi, Bahubhir, Yoh, Nalabhya. What is not understood even by repeated listening, what cannot be grasped even by logical argumentation? So it is a process which is little difficult. You have to go through the process of Shravana,. Manana, Nithyaji, Dhyasana, again and again. All those things we will see in the course of the story itself. And the fact that by this knowledge, one can attain immortality, one can go beyond death. Where did this idea come from? It comes from sources like this