What is simple?

The Merriam-Webster Dictionary gives various definitions for simple: innocent, modest, stupid, credulous, unmixed, fundamental, etc.

In a world so seemingly complex as ours, what is simple?

I remember standing at a street corner in San Francisco many years ago. It was a hot summer’s afternoon, and I was waiting for the bus. There was a flowerbed full of marigolds nearby, and the pungent scent of the dark earth and orange flowers struck me forcefully like a slap. That incident stuck with me all these years.

Many years prior to that experience, I was riding in a truck in Colorado. Awaking after a nap at a stop by a river, I opened the door—sleep still clouding my brain—to be assaulted by a fog of evergreen aroma.

Scent is simple.