Today Ben asked me if parachutes are vehicles. I said no, because they don't have wheels. Then he said vehicles don't have to have wheels and I asked him to name a vehicle without wheels to which he replied, "Feet."
Five seconds after that he asked me if rockets have wheels. I said "No," and yielded to his victory. And later--you know, like with all great comebacks--I realized that the Space Shuttle does have wheels. So that's a total burn on Ben!