Why didn't Dev recognize Sai Baba when he appeared as a Sanyasi?

Dev failed to recognize Sai Baba in the form of a Sanyasi due to a specific sequence of events that created a 'delusion' in his mind. The source material in Chapter 40 explains that this Sanyasi had first appeared at Dev's home for his own purpose: to collect funds for cow protection. This initial visit happened before Dev had even extended the invitation for the Udyapan ceremony to Sai Baba. Consequently, when the same Sanyasi returned with two companions for the meal, Dev's mind concluded he was simply a guest who had come for food, not Baba in disguise. Dev later lamented this, realizing his vision was confused because the first meeting was for a different reason, which prevented him from connecting the Sanyasi to Baba's promise.