I'm convinced that as soon as the first cave dweller taught the second to grunt, the second complained about the first grunting too much.

People will complain about anything. If you've ever worked in customer service, retail, or media, you know that human beings have an uncanny ability to find any little thing to be unhappy about and can achieve remarkable decibel levels when they decide you're the one who needs to hear about it.

Today we have so many outlets for complaining, from social media to Yelp to comment cards both physical and digital. It's easy to forget about the human being on the other end of those complaints and take our ability to just put our ideas out there into the world on a whim for granted.

It's difficult to imagine a time when the vast majority of people were illiterate and had no way of writing down their ideas, but in ancient Babylon, one man found a way to let a copper ingot merchant know that his customer service was lousy.

Full disclosure: I learned about this today thanks to...you'll never believe it...a Simpsons meme. I can't share it here because it's from a private Faceboook group I'm in called Mostly from Sugar Packets: Simpsons Historyposting, but if you're a Simpsons fan who loves history and has a great sense of humor, definitely ask to join. (A video for reference.)

Anyway, the subject of the meme was a clay tablet called 'Complaint tablet to Ea-nasir'. According to Wikipedia (about as reliable as sugar packets), the tablet was used to write a complaint letter back in 1750 B.C.

A man named Nanni had agreed to buy some copper ingots from a man named Ea-nasir, who'd recently picked them up in the Persian Gulf and taken them back to Mesopotamia to sell.

The deal did not go well.

The Ancient Origins website has a full translation of the complaint letter. Here's the gist.

Apparently, Nanni had already paid for the copper. He sent a servant to pick it up, and the servant was treated rudely by Ea-nasir. The servant was presented with copper ingots which were not of the quality agreed upon and was basically told, "Take it or leave it."

Now, I love this quote from the letter:

"What do you take me for, that you treat somebody like me with such contempt?"

That's right - even in ancient times, people said, "What do you take me for?" How great is that? (Ok, I know it's a translation, but the spirit was there.)

To make matters worse, this wasn't even the first time Ea-nasir had been a total jerk to his customer. Nanni accuses Ea-nasir of rejecting multiple requests for a refund and of sending his servants back empty-handed several times through enemy territory.

Nanni ends the letter by saying he'll only buy from Ea-nasir again on the condition that he deliver the goods to his yard so he can personally select which ingots he wants.

So, unlike the guy complaining about coffee being hot or the lady screaming at an H-E-B employee for politely asking her to wear a mask in the store, Nanni actually had valid complaints.

As cliched as the saying is by now, it's still true: The more things change, the more they stay the same.

Poor Nanni had to wait for his messengers to fight through enemy territory in order to tell Ea-nasir what he could do with this crummy ingots.

Today our thumbs can unleash a torrent of complaints in the blink of an eye.

The thread connecting us with Nanni is our burning desire to tell someone all about it.

The tablet is on display at the British Museum. If you ever visit, I dare you to leave a complaint about the complaint. Just find anything to gripe about. It'll be fun.

LOOK: Answers to 30 common COVID-19 vaccine questions

While much is still unknown about the coronavirus and the future, what is known is that the currently available vaccines have gone through all three trial phases and are safe and effective. It will be necessary for as many Americans as possible to be vaccinated in order to finally return to some level of pre-pandemic normalcy, and hopefully these 30 answers provided here will help readers get vaccinated as soon they are able.

LOOK: 15 Discontinued McDonald's Menu Items

More From KTEM-AM