When I was in middle school, our class went over to the high school machine shop for a field trip and some exploratory exercises. On this particular field trip, we were tasked with building a car out of popsicle sticks and paper that would be able to withstand a catapult launch into a wall without compromising the passenger cabin. Weird, I know. My friends and I built out a car where the passenger cabin was reinforced with popsicle sticks, and the engine block area was outlined with paper tubes. This in accordance with what we had seen and heard about crumple zones as sacrificial protectors.
Come time when we were testing out these cars, our car worked magnificently. The crumple zone failed as expected and no damage was suffered to the passenger cabin. A lot of other cars failed in spectacular ways, on one instance decapitating the lego man that was sitting in the driver's seat. We performed among the best if not the best. So imagine our surprise when our teacher came over and gave us a B.
We were screaming how we passed the test and how it wasn't fair. So then she uncrumpled our crumple zone, rolled up a ball of paper, and then stuck it into the engine block, thereby serving as the engine. Then she explained how the passenger cabin would be even safer if the engine was there, and how it might protect the value of the car. We were quite quiet.
I learned two lessons that day: there's always room to improve, and even if you think you do everything right, you can still lose.