When you are pursuing pleasure, you experience imbalances in life. The pursuit of sensory objects is the pursuit of pleasure (bhoga). This happens to you every day, 365 days a year, throughout your life. The association of the senses with sense objects remains established throughout. When this association persists, negative factors influence the psychological body so that you are subject to diseases.
Life is full of happiness and unhappiness, and changes come about in the human body with the onset of these states. The cardiogram, the brain waves and the blood pressure all display changes depending on your state of joy and sorrow. However, if you practise yoga, balance is attained.
It is not possible to withdraw from the world of senses. You have to stay within their influence, it is your compulsion; you are helpless against them. Every one of us has to stay in this world of happiness, unhappiness, passion, anger, envy and delusion. This is the nature of prakriti. Death is a reality and life is a reality too. It is impossible to experience total fulfillment in this lifetime. That is not the nature of prakriti. If you were to experience nothing but happiness from birth to death, you would go mad. Unhappiness comes to balance out happiness, and happiness comes to balance out unhappiness. Just as the day dawns to balance out the night and the night sets in to balance out the day, in the same way you need yoga to smooth out the imbalances created in the body due to the pursuit of pleasure.
In the state that society exists today, we complain about everything all the time, whether in newspapers, television or our conversations. No one is happy with anything. This is how life is perceived. However, your perception of life should be such that you develop a sattwic state of mind. This is necessary not just for the individual, but for society, the family and the nation. If, with the practice of yoga, you are able to change the direction of your mind, it is possible that a positive thinking pattern will emerge from within.