Can you summarize Shri Sai Baba's experience and relationship with his own Guru as described in the text?

Chapter 19 offers a deeply personal account of Shri Sai Baba's time with his Guru. For twelve years, Baba served his master with unwavering dedication, even though he initially longed for a secret mantra that was not immediately given. This period was a test of his patience. The relationship was characterized by profound love, with Baba describing his Guru as an 'idol of devotion and love.' He recounts how he would gaze upon his Guru's face day and night, feeling no hunger or thirst, so absorbed was he in this contemplation. As Chapter 19 illustrates, the Guru provided for all his needs and offered constant protection, expecting nothing in return but this focused, loving devotion.