The nose knows:
The whiff of fiberglass resin take me back to working on the Chinook CH-47 prototype ducts at Vertol before Boeing.
Also, nostalgia of the smell in early Lionel smoke.
My bag of Lichen.
The odor of early hot open frame motors.
Differential gear oil.
Pine scents of smoking PW building chimneys.
The odor of first opening an early MRC power pack.
Plus, as mentioned above, the formaldehyde in plywood. Not healthy but nostalgic non the less.