What was the specific reason Dev failed to recognize Sai Baba when he appeared as a Sanyasi?

Dev's failure to recognize Sai Baba was due to what he later called a "delusion" caused by a specific sequence of events. Chapter 40 explains that before Dev had even formally invited Baba to the Udyapan, a Sanyasi had visited him to collect funds for cow protection. When this same Sanyasi later appeared during the ceremony and was invited for the meal, Dev's mind processed it as the return of the fundraiser, not as Baba in disguise. He later lamented that because the Sanyasi's first appearance was for a different purpose (collecting funds), his vision became confused. He also admitted that he forgot to pay attention to Baba's specific words that He would come with two others, which would have been a crucial clue.