We know not to call animal control if it rains cats and dogs, and even the most literal person won’t reach for a broom if someone spills the beans. Why we say what we do seems like a mystery, but most of the colorful phrases in our collective speech are rooted in history, fable, or myth. A few with surprising backstories:

Scholars think “spill the beans” originated in ancient Greece, where voters cast ballots with white or black beans. If a clumsy voter knocked over the jar or helmet that held the beans, the secret was out.

The origin of “raining cats and dogs” is a little murky. According to one account, heavy rains in 17th-century England turned city streets into rivers that carried trash, along with dead cats and dogs. A less grisly story attributes the phrase to howling wind, which sounds like cats and dogs fighting.

In ancient Rome, the general and politician Pompey believed salt was an antidote to any potential poison in his food, so he added a grain of it to everything he ate or drank. That’s why when people are skeptical of something, they “take it with a grain of salt.”

In the Middle Ages, scholars wore a square cap similar to our graduation mortarboard. People believed the hat actually helped its owner think — and the term “thinking cap” was born.

No one knows the origin of a “skeleton in the closet,” but here’s one theory: Until the Anatomy Act was passed in England in 1832, it was illegal to dissect a body (executed criminals excepted), and doctors were allowed to work on only one cadaver during their careers. Those who didn’t want to get rid of the skeleton kept it hidden in a dark corner or hung it in a closet.