I was reminded of this while booking an airline ticket. I'd found the perfect flight at a price that fit my budget. Halfway through booking, an error message appeared: That fare is no longer available. If I wanted the exact same seat on the exact same flight, I'd have to pay significantly more. My heart started pounding. I started sweating. The voice in my head screamed, "That's it. I'm never traveling again." Nothing dangerous had happened. Yet my body reacted as though it h