Human Beings live in illusion- illusion of hope, future and tomorrow. Man cannot lead life with the reality - he needs dreams, he needs illusion, he needs to exist. Very deep understanding should be there without which entry into the inquiry is not possible which is called YOGA.
 

Observing the Swara:
Strong inhaling from the nose allows the individual to understand which nostril has a dominant flow at a particular time. The stronger nostril-flow will have a particularly heating or cooling effect. At any given time, in the human body, only one nadi or nostril-flow, the left or the right, will be dominant. The left flow is known as IDA NADI or CHANDRA NADI, relating to the moon; and the right flow is known as PINGALA NADI OR SURYA NADI, relating to the sun.