People here are really taking offense to the characterization of 18 y/o this way since the first thought is to see where they fit in this model of reality. But

People here are really taking offense to the characterization of 18 y/o this way since the first thought is to see where they fit in this model of reality. But the author isn't speaking about individuals but aggregates; on the average, the 18 y/o American kid is most likely unsure about what they want to do in their lives, and are thrust into an extremely competitive zero-sum environment of college. All the author is saying is that this isn't representative of the real world, but people that go through this trauma might continue to think this way into adulthood, leading to a toxic culture and paradigm of the world.