Nothing is more memorable than a smell.  One scent can be unexpected, momentary and fleeting, yet conjure up a childhood summer beside a lake in the mountains; another, a moonlit beach; a third, a family dinner of pot roast and sweet potatoes during a myrtle-mad August in a Midwestern town.  Smells detonate softly in our memory like poignant land mines hidden under the weedy mass of years.  Hit a tripwire of smell and memories explode all at once.  A complex vision leaps out of the undergrowth.  ~Diane Ackerman, A Natural History of the Senses