Oh man, smell is the strongest trigger of memories I have experienced.
I walked into a cobbler's shop a few years ago and got hit with that leathery, tannery smell. It sent me back 40-45 years to a shoe repair shop I used to stop into on way home from elementary school to talk to its owner Ike. Until that day I had never thought of Ike and the shoe shop, ever. What a nice man he was!