A quote from Joe DiMaggio ends the book. DiMaggio is a famous baseball player, and baseball is one of Zinsser's big interests. Zinsser admires how DiMaggio always does his best while playing ball. The quote has to do with how Joe does not want to disappoint a fan who might be seeing him perform for the first time. Zinsser implies a strong parallel for writers: writers should always strive to satisfy a new reader by always doing the best work possible.