By going out and distributing books, I was forced to be more outgoing and to start thinking about others. Gradually, I got a wonderful taste from distributing books. It took several years, but when the taste came, it gave me enough of a realization to know that that is where the taste was to be found. That spirit which I imbibed from distributing books carried me forward and brought me to the level of preaching, and I began experiencing that same taste from preaching as I got from distributing books. It gradually became more and more obvious to me that preaching was something that must be very pleasing to Srila Prabhupada. Otherwise, how could I feel so much spiritual satisfaction from it? From that time on, I just kept on preaching and, gradually, taking sannyasa came naturally as a result of my desire to preach more and more.
(Collected Letters to My Disciples, Vol 3, Pg 119 1st Paragraph)