The reason is not so much to show you how to fasten it, but to show you how to unfasten it. Sure you know how to use them in your car, But that’s precisely the problem. You do it dozens of times a week.

But car seat belts work differently from the “lift the buckle” way that airplane seat belts release. And in a panicked emergency, passengers might not be thinking clearly. Fliers who are disoriented or mentally incapacitated — barely awake before a 6 a.m., takeoff, jetlagged after a long flight, or under the influence of Ambien or alcohol — have been known to reach to the right or left near their thighs, as you would in an automobile, trying to push a seat belt release button rather than reaching for their laps and lifting a flap. In other words, previously established “muscle memory” works against you in a crisis. That’s why it is in the safety briefing - hopefully the information will somehow filter through if you ever really need to use it.