Who is the most disappointed medalist at the Olympics? How do brains simulate what might have been? How can you get your kid to wear a jacket in the cold? What if you had to face more successful versions of yourself? And what does any of this have to do with why menus should be shorter, why empires divide, and why you should always put yourself in the shoes of future people? Join Eagleman to learn the capstone secrets of mental time travel, and what these have to do with the emotions of regret and relief.