Describe the sequence of events that led Dev to feel that Sai Baba had disappointed him.

Dev's disappointment was the result of a misunderstanding and a failure of perception. The events described in Chapter 40 began when Dev invited Baba to his Udyapan ceremony, and Baba agreed to come. A Sanyasi, who had previously visited Dev to collect funds, arrived for the meal with two companions. Dev served them but did not recognize Baba among them. Because his mind was veiled by the memory of the Sanyasi's prior visit for a different purpose, he remained doubtful. As Chapter 40 recounts, after the guests left, Dev felt that Baba had not fulfilled his promise to come. This led him to write a sorrowful letter to Jog, complaining that Baba's assurance turned out to be false and that he was left with no profound experience.