You’re in a museum looking at a World War II airplane full of bullet holes. A sign explains how engineers studied those holes to figure out where planes needed extra armor. Sounds smart, right? But wait—someone points out something important: these were the planes that came back. What about the ones that didn’t? Maybe the damage on those would tell a totally different story. Suddenly, you realize there’s a flaw in the logic. What’s missing? What trick is your brain falling for? Take the quiz to find out what’s really going on here.