Based on the twelve-year service to his own Guru, what did Sai Baba learn about the ideal state of a disciple's devotion?

The account in Chapter 19 reveals that the ideal state of a disciple is one of total, loving absorption in the Guru. The narrator describes serving at his Guru's feet for twelve years, during which time his heart was filled with immense love. The disciple's role was to maintain constant contemplation of the Guru, gazing upon his face with such love that feelings of hunger and thirst would vanish. This intense focus was the only thing the Guru truly desired; he 'desired nothing more than this.' This experience teaches that the highest form of devotion is a restless mind without the Guru and an unwavering focus that makes the Guru one's sole meditation and goal.