Scent is associated with memory. Olfactory bulbs, the receptor of smell, are connected to the brain where memory and associated learning center is located. First encounter with scent occur in childhood, so most scent brings memories from childhood. Human associate scent with occurring event, which makes a scent pleasant for one, the same scent is unpleasant for another one. For example, scent of flowers remind us of spring, to others it bring memory of exam evoking anxiety to them.