The document discusses memory decline and amnesia. It explains that the hippocampus plays a key role in forming and consolidating memories. It describes two types of amnesia caused by either brain trauma or neurodegenerative diseases like Alzheimer's. Retrograde amnesia involves the inability to remember past events, while anterograde amnesia is the inability to form new long-term memories. Finally, it notes that some memory decline is normal with age, especially for episodic memory, but that decline is not inevitable and can depend on factors like motivation and nervous system health.