Have you ever found yourself in front of a computer and asking it aloud: “Why?” We have constructed a cognitively motivated episodic memory system that enables a virtual guide to respond to this question. The guide, a virtual agent based on a belief–desire–intention (BDI) architecture, is employed in a Virtual Reality (VR) scenario where he accompanies a human visitor on a tour through a city. In this paper we explain how the agents memorizes events and episodes according to an event-indexing model and how the interaction is enhanced by using these memories. We argue that due to the cognitively motivated nature of the event-indexing model every interaction situation can be described, memorized, recalled and explained by the agent.