What this shape contains
There is a hippocampus in each medial temporal lobe. It is folded cortical tissue, not a solid "memory box." The wider hippocampal formation includes neighboring structures such as the dentate gyrus and subiculum, which participate in interconnected circuits.
Remembering an event
Remembering a conversation involves more than recognizing the words: it includes where you were and what happened. The hippocampus helps form memories of events and their context, working with surrounding medial temporal and other cortical regions.
What the evidence tells us
Patient H.M. had profound difficulty forming new memories of facts and events after bilateral medial temporal surgery, while some skill learning remained possible. His surgery affected more than the hippocampus, so this is evidence for a memory system, not proof that all memory lives in one structure.
Space, as well as memory
In rats, O'Keefe and Dostrovsky found hippocampal neurons whose activity depended on location. This helped establish the study of place cells and spatial representation; it does not mean the hippocampus is a literal GPS or works alone.
What the model leaves out
Only the gross shape is shown. CA subfields, the dentate gyrus, microscopic layers, and connections are not individually segmented.