Based on Chapter 5, what is the key lesson about choosing a Guru, and how did Sainath himself demonstrate this principle?

The central lesson presented in Chapter 5 is that for spiritual liberation, one must choose a Guru. The text explicitly states, 'Whether one should become someone's or make someone one's own, there is nothing better than this; otherwise, one cannot cross to the other shore.' This principle is powerfully demonstrated by Sainath's own behavior in the story of the man who mistakenly thought he was Sai's Guru. Even in that situation, Baba maintained the feeling that 'His Guruship to him, and my discipleship to me.' As this chapter illustrates, Sainath himself practiced this lesson, showing that making a firm resolution to follow a Guru is the path to climbing the 'fort of selflessness.'