World Model
A human who has never seen a ball thrown on the moon already knows it will fall back down. They don't need to have seen it happen. They understand gravity. They have internalized the laws of physics well enough to make predictions about situations they have never encountered. That is what a world model is: a representation of how reality works that generates correct predictions about new situations, not just recall of seen ones.
Current AI has no equivalent. It has read every physics textbook ever written, and still cannot reason about the world the way that a human can, because it has patterns about physics, not an understanding of it.
Living Memory maintains a real world model. When the world changes, the system's beliefs update automatically. This is what it means for an AI to actually know something about reality, not approximate it.