Before sight. Before explanation. Before story. There was scent. Bad smells taught us to survive. They sharpened our senses. They made the body lean away. Pleasant smells taught us to approach. To bond. To remember. The brain still listens. Orbitofrontal reward circuits. Amygdala memory pathways. Signals moving faster than thought. But scent is not only threat. Not only pleasure. It is memory architecture. Olfactory Signals: Pleasant vs Unpleasant Smell as Cues Research sug