RF,
Have you ever read Remembrance of Things Past, by Proust? Swann's Way, the first book in the series, has a lot to do with the way certain objects and smells -- the dipping of cake in a cup of hot tea, say -- can reinvoke memories long forgotten, that might otherwise remain buried ...
For me it's the combined smell of chalk dust and pencil shavings. I am seven years old and ascending the rickety wooden staircase of my elementary school, running my hands over the grooved banister, ready to pass through the heavy green doors. There is a library book in my lunchbox that I plan to hide behind my notebook while the teacher drones away, and I can't wait to get out of my goulashes and behind my small desk, behind Genevive Vialobos, whom I am following up the stairs, whose long dark hair will entrance me between chapters.
I know what you mean: it's powerful, transformative, if only for a moment.
Dedalus