You are on a flight. The safety announcement begins. The flight attendant says: in the event of a loss of cabin pressure, oxygen masks will drop from the overhead panel. Pull the mask toward you, place it over your nose and mouth, and breathe normally. And you... look at your phone. Now imagine a different announcement: before we take off, I want to point out something that surprises most of our passengers. If the oxygen masks fall, put yours on first before helping the child next to you. Your instinct will be to help the child first — but if you pass out trying, neither of you survives. That version gets heads up. This is the second principle of Made to Stick: Unexpected. To get attention, you need to violate a person's expectations. To hold attention, you need to open a knowledge gap — and then fill it. The brain is essentially a prediction machine. When everything goes as expected, the brain processes on autopilot. Surprise breaks that autopilot, forces attention, and creates a moment of genuine engagement. But surprise alone is not enough. A cheap trick might turn heads once. What sustains attention is curiosity — and curiosity, the Heaths argue, comes from knowledge gaps. The psychologist George Loewenstein described curiosity as the feeling we get when we notice a gap between what we know and what we want to know. That gap creates an itch that only new information can scratch. The best communicators do not open by demonstrating how much they know. They open by showing the audience what they do not know — and then making them want to find out. Think about how a great teacher begins a lesson. Not with the answer, but with a question or a puzzle that makes the answer feel urgent. Not: today we will learn about the water cycle. But: why does it never actually run out of water on earth, even though billions of people use it every day? Oluwaseun is building a community app. When he pitches it, he usually starts with: I built an app that helps people find services nearby. He gets polite nods. A better opening: more than 40 percent of people in Lagos spend over an hour trying to find a reliable plumber, carpenter, or electrician — not because they do not exist, but because there is no good way to find them. That gap is what we are fixing. Same product. Different opening. The second version opens a gap that the audience now wants to see closed.