Aeon: How exactly does smell unlock buried memories from the past?

The key to this special association between smell and first-formed memories appears to involve an area of the brain called the hippocampus.

Now, let's take this a step further. I can be in desperate, life-threatening crisis, resolve the crisis using something I learned from a person in my past, and sometimes smell a smell I associate strongly with that very person in my past. A smell that could not possibly be generated in that location. A person deceased. Heavenly assistance? Science tells me I'm nuts. But I go with it. And appreciate it.