The document discusses different types of memory including semantic, episodic, and procedural memory, and how damage to areas like the temporal lobe and prefrontal cortex can impair semantic memory. It also describes how without certain types of memory, everyday skills like walking, speaking, and recognizing objects would be impossible. The document examines the story of patient H.M. who helped researchers discover the separation of declarative memory into two parts after undergoing brain surgery that impaired his ability to form new memories.