you quoted jamie oliver, a great example. >> yes.s, okay, let's talk about these issues that really matter and start quoting stats. whatever. he came on and said, this was the opening sentence, like, in the next 18 minutes, four americans are going to die because of the food they eat. boom. he's got you. you have to listen now. >> that's how long the talks are, 18 minutes. >> 18 minutes. >> how did you determine 18 minutes? >> it's a natural human attention span. it's hard to persuade people to concentrate for more than that, but it's long enough to unpack an idea to say something that matters. >> you, you know, in reading this, you said a talk is more powerful than anything in written form. there's now this renaissance of public speaking. i love you talk, too, about presentation literacy is something that should be taught in schools. >> well, i really think is should because what's changed is that ten years ago, there was this moment where all ancient art -- it is an art, public speaking, could scale. it was captured on video and sh