Former teacher here. Your example of the USSR is a good one to demonstrate the importance of a broad base of knowledge. In order to actually understand what "the Soviet Union collapsed" means, you need to know facts about what precipitated the Cold War. What communism means, what democracy means, and so on. Where Russia is on a map, and what "satellite" countries are. These are all concepts, too, but more atomic that build to the bigger idea.
Any "concept" is composed of interrelated facts, all the way down.
Any "concept" is composed of interrelated facts, all the way down.