Baba speaks of Pravrutti and Nivrutti. Can you explain the difference between these two states and how they relate to happiness and sorrow?

According to the teachings in Chapter 17, Pravrutti is the state of worldliness, characterized by the dualities of friends and enemies, attachments, and worldly affairs. In contrast, Nivrutti is the state of cessation, achieved through knowledge of the Self, where such distinctions disappear because one perceives only the Self everywhere. Chapter 17 highlights that someone who has attained the supreme happiness of Nivrutti finds the great sorrow of the body to be miserable in comparison and would not cry for lesser worldly happiness. Such a person becomes like a mountain of courage, unshaken even if 'mountains of worldly sorrow collapse upon him.'