What was the specific reason for Dev's failure to recognize Baba in the guise of a Sanyasi?

Dev's failure to recognize Baba was due to a 'veil of Maya' created by a prior encounter. According to the detailed account in Chapter 40, the Sanyasi had first appeared before Dev had even extended the Udyapan invitation to Baba. That initial visit was for the purpose of collecting funds for cow protection. Because of this, Dev's mind categorized the Sanyasi as a fundraiser. When this same person returned for the meal, Dev's perception was already fixed, preventing him from inferring that it could be Baba in disguise. He later lamented this delusion, realizing his pride and lack of attention to Baba's specific words about bringing 'two others' had confused his vision.