Knowledge
Today, knowledge is much less valuable. You can master anything from calculus to molecular biology by browsing Youtube and the Khan Academy. In this always-on Wikipedia world, the internet is much faster, better and cheaper than you at producing knowledge.
Just being able to provide facts makes you a replaceable commodity. Yet, much of school is that. Being able to know the 5 Ps of marketing on the tip of your fingers. Or the parts of the inner ear. Or reading the linear algebra textbook and applying Cramer’s rule flawlessly.
If you’re going to school to get knowledge, you’re doomed.
On the other hand, if you’re in school to develop unique and remarkable insight in your field, you win. The world needs people who can see things differently and provide genuine expertise in your field. Who can take the knowledge of others and draw unprecedented insight. It means taking a stance on issues, disagreeing with professors and getting involved. It means writing game-changing papers, even if that involves poor marks from a stubborn professor.
Two completely different worlds.