What makes a human life 'useless' according to the philosophy in Chapter 8, and what is the path to a 'successful' birth?

According to the philosophy presented in Chapter 8 of the Sai Satcharitra, a human life is considered useless if it is wasted solely on the four activities of eating, sleeping, fear, and mating, which are common to animals as well. The text poses the question of what distinguishes humans from dogs if these are the only pursuits. The chapter defines true success for a human birth as the 'realization of the Eternal.' A person who understands their origin and the reason for their birth is considered proficient, while a life without this understanding is just exhaustion and ultimately wasted.