As Way of the Dragon says, "there are two concepts taught by Shinsei: what you show and what you do not show." These aren't just words on a page...it's a principle to guide you when you are trying to "defeat" an opponent. When you're gamemastering, the "opponent" is the player who is determined not to be surprised, amused, or terrified. In order to "defeat" their disbelief, their jaded, complacent attitude that they will not have fun despite the fact they chose to spend their Saturday night at your house, you've got to make them have an emotional reaction through your words.