An agent's ways of carrying forward what matters, sorted in this book by the office furniture it resembles: episodic memory is the logbook (append-only records of what occurred), semantic memory is the filing cabinet (facts, needing curation because they go stale), and procedural memory is the procedures manual (how to behave—the sharpest object in the room, because an entry is the agent's future behavior). Short-term memory is simply the message history (Chapter 9).