Studies have shown that people can recall a scent with 65% accuracy. Because smells are processed by the same part of the brain that handles memories and emotions - the temporal lobe - we respond to them with rare intensity. Decades later, a passing scent may summon a pleasant memory. One so vivid that we seem transported across time and space.
The human nose is something of a marvel. The nose can determine where a smell is coming from, pointing you - for better or worse - toward the source.
Our sense of smell is deeply individual: Some people can't smell mushrooms; others can't sniff out freesia. These differences are mostly genetic to enhance or diminish our ability to detect odors.
In fact, it's believed that we never experience a smell the same way twice, since the sensitivity of our nose changes from hour to hour and day to day.