What was the 'miracle' that Sapatnekar witnessed, and what did it make him understand about Sai Baba?

The miracle Sapatnekar witnessed was hearing his own life story being told by Sai Baba to a Dhangar woman who had no connection to it. Chapter 48 details how Sapatnekar listened carefully and was shocked to find every word of the conversation was his own story, even mentioning the death of his son. This event had a profound impact, filling him with "great wonder" and etching a deep respect for Sai's feet in his mind. He realized that Baba was a "great knower of the inner self" and that everything was as clear to Baba as a "gooseberry in the palm of the hand."