I'm Shankar Vedantam, here to tell you about a great mystery.

That mystery is you.

As the host of a podcast called Hidden Brain, I explore big questions about what it means to be human.

Questions like, where do our emotions come from?

Why do so many of us feel overwhelmed by modern life?

How can we better understand the people around us?

Discover your hidden brain.

Find us wherever you get your podcasts.

You're standing on top of a rough and rugged hill.

Part of a crumpled landscape of yellow-brown rock covered in patches of green,

grassy vegetation. It's a sunny, clear day, and from your perch, your view is nothing short of

glorious. Looking west, the endless blue waters of the Atlantic Ocean stretch off into the horizon,

its waves gently lapping against the shore below you. A refreshingly cool

sea breeze hits your face, a welcoming respite from the sweltering heat of the sun. You close your

eyes and let the breeze envelop you for a moment before turning around. As you open your eyes again,

this time facing east, the view couldn't be more different.

A vast, arid basin reaches as far as the eye can see.

It's deep, stretching several kilometers below the sea level of the Atlantic Ocean behind you.

The ground at its base glitters with salt and mineral deposits, but otherwise it looks barren, devoid of water,

of plants, of animals, of anything, really.

The contrast between the two landscapes couldn't be more apparent, and the narrow hill you're

standing on that separates the ocean from the desert isn't just a stretch of land at all.

...