Through practice and experience the mind will settle down. It is through experience that one feels dispassion/detachment (vairagya).
What is dispassion? As a child, you would get excited about cotton candy, as though eating it was the sole aim in life. Chocolate, cake and ice cream were everything to you. But as you grew older, you became indifferent to candies and chocolates and were drawn to attractive young men or women. With age, the looks of a person also ceased to attract your attention. This is known as dispassion.
In every human being’s life, some dispassion comes in naturally. But through knowledge, dispassion comes in more quickly. Otherwise, the dispassion does not mature and trickles in here and there. But if there is sharp intellect, knowledge and good satsang, dispassion comes in like a jet plane. Dispassion is not being apathetic, that everything is useless, pointless, but the attitude of ‘Been there, done that; I am above all this.’ A joyful, carefree state of being is known as dispassion.
Often, those you consider dispassionate are depressed. That is why some people are scared of those claiming to be dispassionate. Adi Shankaracharya has said, ‘Kasya sukham na karoti viraagaa’ meaning, ‘What kind of joy does dispassion not bring?’ All kinds of joy and comforts come naturally to you, without your making any effort. That is why through practice and dispassion this restless mind becomes still.