Prabhupada asked George [Harrison] if he was reading his books at all. George said he was, mainly the Krsna book. "Mukunda gave me the new books, but there's so much in, ah, there's just so much to read. I don't know how anybody could have written it; it's difficult enough to read all that amount."
Prabhupada acknowledged his appreciation. "Sometimes they are surprised how one man can write so many books, but it is Krsna's grace," he said humbly. "Otherwise not possible. For a human being, it is not possible."
(From "Transcendental Diary" by Hari-sauri Prabhu)