Onion

It's kind of like peeling an onion. You keep digging deeper, figuring you are going to get to the heart of the matter, and as each layer is peeled away the onion gets smaller and smaller.

You get to the end of the peeling process and all you're left with is a bunch of layers sitting on the cutting board. The essence of "onion" is the accumulation of layers.

There is no other essence beyond the layers. Or at least not one you can see.

You realize that's the story of your life...

You are no wiser, but you have the makings of a hell of a sandwich!