Desire is the root of all knowledge, action and thinking. We believe that success is to achieve all we desire. Yet most of us do not succeed in fulfilling most of our desires despite sincere efforts.
The eighth chapter of the Chandogya Upanishad drives home the fact that a state of total fulfillment of desires (satyakama) is attained through Brahmavidya - the knowledge of the ultimate Truth which results in Self-realization whereby one remains untouched by any situation in life.
Indra, the king of heaven lived for 101 years in the hermitage of Prajapati, the Creator, in order to gain the knowledge. A life of self-control and meditation on the heart-space was the means taught, and total freedom and fulfilment, the goal achieved.
Swamini Vimalananda's appropriate notes will surely add a new dimension to our understanding to this text.