1. History, as it relates to today. It's important for the coming generation to recognize the ebbs and flows of humanity. The media wants to say that "this scenario is unprecedented and scary, and you should be worried". History shows that most things are "another one of those" (credit to Ray Dalio).
2. Retirement planning. At age 18-25 you have the greatest opportunity to significantly influence your future success, but many people miss that opportunity.
3. The Way The World Works. Idealism is nice and should be pursued, but you will not be successful in that pursuit if you are ignorant of the way things are (even if the way things are is wrong). Learn and understand the system, work the system, and you'll then have the best chance to change the system for better.