Why do smells trigger such strong memories?

Smell is unusual because odor signals travel from the nose to brain circuits closely connected with the amygdala and hippocampus. Those regions handle emotion and memory, so a scent can act like a powerful cue for retrieving old experiences. This is why perfume, food, or a place’s smell can suddenly recreate a childhood moment. The effect is often called the Proust phenomenon, after writer Marcel Proust, who described a madeleine evoking memories. Scientists have long noted that smell-based memories can feel especially vivid and emotionally loaded.