Why did Sai Baba choose a cynical and argumentative person to write His life story?

According to the excerpts from Chapter 2, Sai Baba's choice was a profound act of grace and an illustration of His divine power. He looked upon the author's impatient mind with compassion and sought to provide him courage. More importantly, Sai Baba declared, 'He is merely a pretext; I myself shall write my own story!' This statement, found in Chapter 2, reveals that the author's personality flaws were secondary to the divine will acting through him. Sai instructed the author to dissolve his ego and surrender completely, promising that if he did so, Sai Himself would enter and write the story. The task was therefore a spiritual path for the author's transformation and a vehicle for Sai to fulfill the devotees' wishes.