How does suffering in worldly existence (Samsara) lead to the pursuit of Shreya, as detailed in Chapter 17?

According to the teachings in Chapter 17, the relentless suffering within worldly existence, or Samsara, is often the catalyst for seeking a higher path. The text describes how a person suffers from "three unendurable torments" (Tritapa) and becomes exhausted by the sorrows of life. It is at this point, when the pain becomes extreme, that a person begins to search for a way to stop the incessant spinning of the wheel of existence. As stated in this chapter, when this thought arises by great fortune, true human effort (Purushartha) is born. This newfound purpose then leads the individual to choose the successful means for their own true self-interest, which is the path of Shreya.