When Srila Prabhupada requested me to read Bhagavad-gita 16:23 during his darsana with Alice Coltrane, I could not find the verse at first; and Srila Prabhupada chastised me for not studying his books. "You must be like an expert lawyer who can give all the references from law books in order to win the case." I told Srila Prabhupada that I wanted to read his books but found too little time because of my heavy work schedule. Srila Prabhupada demanded, "You have to find the time. Less eating and sleeping." He quoted the verse describing how the Six Gosvamis overcame their animal functions. He concluded, "It requires practice."
From TKG's Diary.