112.

"In the whole world there is no study so beneficial and so elevating as that of the Upanishads. It has been the solace of my life; it will be the solace of my death. They are products of the highest wisdom."
  — Schopenhauer

The Upanishadic seers felt no necessity to go to any spiritual centre, no necessity to go to a temple, no necessity to hear a talk or a sermon or even to study books. God was their only outer book, and God was their only inner teacher. God-realisation was their only necessity, and God-manifestation was their only reality.