For generations, parents and caregivers have tried to teach children the value of a dollar. There are many tools at their disposal — allowances, chores, and of course, piggy banks like the one pictured above. If you had to guess where piggy banks came from, you’d probably concoct a theory around the fact that pigs have a voracious appetite and gobble up everything, and similarly, we want to encourage children to save, so they should feed their piggies with whatever coins they are given or earn.

Makes sense. But likely wrong.

Probably since the advent of coinage, people have been looking for places to keep their money. Sticking dollar bills under the mattress is a relatively new innovation, but putting valuables into jars stretches back centuries. And clay jars have been around for thousands of years, with pot sherds found in China dating back as much as 18,000 years ago, according to the Associated Press. So it only makes sense that early “banks” were simply jars of clay.

According to the Straight Dope, an orange type of clay was rather popular in the Middle Ages, and used for storage of everything — including valuables and money. The jars made from this orange clay weren’t shaped like anything special — and certainly not like pigs. Rather, they probably looked like regular clay jugs, unadorned in order to keep them economical.

That orange clay used to make these jars was called “pygg” and the jars themselves were called “pygg jars.”

Originally, “pygg” was probably pronounced something closer to “pug” than “pig,” but as the language evolved and our pronunciation of vowels shifted, “pygg” became a homophone for “pig.” And at roughly the same time — a few generations different, give or take — the modern meaning of the term “banking” came to be. Together, “pygg jars” became “piggy banks,” and soon after, were stylized to look like the animals from which they do not get their name.

Bonus fact : While children keep their money in piggy banks, we grown ups typically have bank accounts. To withdraw money, it’s common to go to an ATM and enter your PIN. PINs are typically four digits long, although there may be some added security by making the number larger. According to the BBC, the inventor of the ATM, John Shepherd-Barron, wanted to make PINs six digits long, noting that he was able to recall his six digit military ID number. But while discussing the idea with his wife, Mrs. Shepherd-Barron said that she preferred a four digit code, claiming she could only remember four digits. He deferred to his wife and as a result, created the PIN length standard common today.

From the Archives: Sweating Like a Pig: Pigs don’t actually sweat all that much. So where does that phrase comes from?

Related: In case you need a random-ish PIN, here’s a book of a million random digits. Really.