Memory is the process of remembering past experience. Each memory is first processed to make it palatable, and then filed for future reference, leaving an impression in the mind. These impressions can either remain on the surface of the mind and be recalled at will, or sink to the bottom where they take root.Patanjali describes the restless mind as outgoing (paranga cetana) and the quiet inward-turned mind as (pratyak cetana) I.29. When the mind focuses on external influences the Self appears to assume the forms and images projected by the mind. When the vritti activities are quietened through sensory withdrawal, concentration, and meditation, man is said to rest in his true nature.Patanjali gives us two tools which will help us control the mind – abhyasa or regular, sustained practice, and vairagya, a process of detachment from objects of desire, which is attained as a direct result of abhyasa. Patanjali likens both states of mind to a mirror. When the mirror is dusty or smeared, it reflects a distorted image of whatever it reflects. When the mirror is cleaned the image is reflected without distortion, shining in its own essence – samadhi. Patanjali concludes by saying that success in Yoga depends on the strength of our desire for enlightenment, and the amount of effort we are prepared to put into our practice.