You live in a world belonging to " that " . You call " that " Your life and how in "that " storey there is a you with a past present and future . Then longing is the source that never rests , it's was there before you where born it was there at birth and it will be there at death, it's there when you sleep when you dream when you awake . To understand this Longing you will not, nor will anybody.If they say they know , it's then you will come to understand that what they know is there storey and it is there "longing to belong to "That"