The story of the little boy Nachiketa who went to the house of death. The point is Shankara Charya and his commentary says, akya ika ika Vidyaas tuktya. That means knowledge one can go beyond death. We learn so much from this story. This and many more things.
Swami Sarvapriyananda teaches the Katha Upanishad, which is one of the most popular Upanishads. The scripture concerns the story of a young man who goes to the house of death to find out what happens after death. The reply describes the nature of reality and the meaning of life.