Very nice article and well explained. I would like to add following.

When Nachiketa asked and persisted on Knowledge of Life,

Yamraj (Death) said, "Ask for sons and grandsons who will live one hundred years, many cattle, elephants, gold, and horses. Ask for empire on this earth and live as many ears as you like but not knowledge"

But Nachiketa persisted, he was firm as a rock. He said, whatever you will give (material life), I will accept but not in lieu of Knowledge of LIfe.

Then the god of death said, “My boy, you have declined, for the third time, wealth, power, long life, fame, family. You are brave enough to ask the highest truth. I will teach you the Knowledge of Life.
Swami Vivekananda told; If I get ten or twelve boys with the faith of Nachiketa, I can turn the thoughts and pursuits of this country in a new channel.