This book grew out of the comment of a trusted congregation member to the author that 80% of his sermons were immemorable, but that the other 20% had profoundly changed their life. Ellsworth started searching for reasons as to why some sermons had such a greater impact than others. Previously he had dismissed preaching without a written manuscript as being almost certain to be shallow, full of clichis and repetitious. Surely 'deep' teaching needed more support than his poor memory could provide? Launching out in faith, Ellsworth started reducing his notes to the extent that they could be contained on one post-it note. The result? A learned colleague said that you would never have guessed how 'so much effect could have come from a single change.'