How does Chapter 17 define the true purpose of human life, also known as 'Purushartha'?

Chapter 17 defines the true purpose of human life, or Purushartha, as the conscious act of discarding Preya (the pleasant path of worldly joy) and honoring Shreya (the good path of salvation). The text states that this true manhood is born out of great fortune when a person, exhausted by the unendurable torments of worldly existence, begins to search for a way to stop the cycle of suffering. At that point, they choose the successful means for their own true self-interest. Therefore, according to this chapter, Purushartha is the firm human effort to strengthen one's intellect and struggle for the sake of Shreya.