Every human being is at the lowest stage because dhara (current) of every one is flowing downwards (involvement in Material Activities etc) and breath is going from nose to lungs, again downwards. When this dhara is changed to Radha (reversal of Dhara) then current begins to flow upwards (one reaches the highest stage) means breath begins to travel from brain and back bone/ spinal cord. How dhara is converted into Radha that is made possible by 1. Knowledge 2. Practice 3. Imbibing of knowledge (dharan karna).
Note: Hence Radha Grace is Required For Both Personnel Form and Impersonal Form of Meditation
In Mahabharata Karna was gauardian son of radha hence called radhey