A graph. On the x axis is "knowledge of different types of trucks"; on the y axis is "proximity to trucks in daily life". There's a region near the lower end of both axes, tilted to show that they correlate, labeled "Normal people". There's another region near the high end of both axes labeled "People with truck-related jobs or hobbies". There's another region, an outlier with lots of knowledge of different types of trucks but not much proximity to them, labeled "Parents of children age 2-5". Next to this last category are two people, an adult and a child, looking at a truck going past, with the adult saying "You're a truck!"
Title text: …so the most intelligent and least inane people should be those who are extremely close to trucks but don't know anything about them (perhaps because they're too busy working out a resistor puzzle).