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.