As a very young child, I grew up in the remote hill country of the Pacific Northwest. Thirty years later, I moved to Seattle and decided to go hiking in the Cascades. The smell of those mountains immediately unleashed memories I didn’t know I had. It was really unexpected how much memory was keyed to that smell. Also, that smell induced a strange feeling like I was supposed to be there as if it was my native environment, and I hadn’t lived in the region for decades.

I am an avid outdoorsman. One thing I have realized is that every wilderness locale has a distinct natural smell. It isn’t just the plants but also the minerals, soil, and bacteria that live in that environment. There are vast regions of the US where I can probably identify the locale with some degree of fidelity by the smell. It is a bit like how an expert sommelier can identify wines. Civilization is more hit and miss but wilderness is almost fingerprinted by its smell.

Humans are clearly capable of sensing it and imprinting based on it. We don’t think about it much but it is there.