Who was Das Ganu, and what specific challenge led him to seek Sai Baba's help in Chapter 20?

Chapter 20 introduces a story about Das Ganu, who was undertaking a significant literary project. He was creating the "Ishavasya-Bhavartha-Bodhini," a commentary explaining the Ishavasya Upanishad in simple Prakrit language for people who were ignorant of Sanskrit. Although he translated the text word for word, he encountered a major challenge. The Upanishad is described as being full of deep meanings, and Das Ganu felt he could not grasp its "internal secret." This lack of profound understanding caused his mind to find no joy in the work, and it was this specific doubt that he brought to the feet of his Satguru, Sai Baba, in Shirdi.