Ready to have your brain frozen, and then have your mind blown?

Get ready to learn the untold truth of 7-Eleven's famous Slurpee.

The Slurpee's story begins in an unlikely place: a Kansas Dairy Queen with a finicky soda fountain.

It was the late 1950s, and the Dairy Queen's owner, Omar Knedlik, took to storing bottles of soda in the freezer when his soda fountain malfunctioned.

Whenever he accidentally left the bottles in the freezer a bit too long, sodas would emerge from the freezer partially frozen.

To Knedlik's surprise, customers were wild about the slushy soda pops and began requesting them specially.

Inspired, Knedlik cobbled together a machine from a car A/C unit that would churn out semi-frozen, carbonated beverages.

Then, Knedlik partnered with an engineering firm in Dallas to perfect the design, and began selling the newly christened ICEE machine to diners, restaurants, gas stations, and convenience stores.

In 1965, 7-Eleven licensed the ICEE machine from Knedlik and rebranded the drink as the "Slurpee."

7-Eleven ad agency director Bob Stanford was credited with coming up with the name "Slurpee" based on the noise the drink makes as it's sucked through a straw.

When the Slurpee first hit 7-Eleven stores, it was available in two flavors: Coca-Cola and cherry.

By the time the 1970s rolled around, the Slurpee had expanded to 27 different flavors.

Some of their names were: For Adults Only, Red Eye, Scooby Doo, Green & Wet, and, uh...Bull Corn?

Since the Slurpee's inception, 7-Eleven has ditched some of its more adult-sounding names, but introduced hundreds of flavors.

In the U.S., some of the most popular flavors are Fanta Wild Cherry, Coca-Cola Classic, Fanta Banana, Barq's Root Beer, and Mountain Dew.

Slurpees are, and always were, a cool kid's drink.

From the beginning, Slurpee marketers targeted kids, teens, and young adults with psychedelic cup designs and groovy jingles.

The grooviest of all these melodies was arguably "Dance the Slurp," a full-length jingle written by Tom Merriman, one of America's most influential jingle composers.

It's a lively, two-minute tune that consists of funky brass music and slurping sounds, punctuated with people occasionally exclaiming, "slurp, slurp!"

The song was released on vinyl 45 in the 1960s and handed out for free at 7-Eleven stores.

Years later, "Dance the Slurp" was remixed by Cut Chemist and DJ Shadow in their 1999 album Brainfreeze.

Today, copies of the original "Dance the Slurp 45s " can fetch a few bucks on eBay.

Remember that dark time in human history when you had spoons and you had straws, but nothing in between to down a milkshake with?

The Slurpee solved this culinary quandary with the introduction of its signature spoon straw.

The pioneering utensil was developed by Arthur A. Aykanian, an industrial engineer who trained as a mechanical engineer at MIT.

Since the release of the spoon straw, 7-Eleven has introduced additional, limited edition Slurpee straws, including collectible tongue straws and Deadpool-themed straws.

Kosher is a certain type of food preparation that complies with strict Jewish laws.

Kosher rules can be pretty complex, restricting the way certain foods can be harvested, processed, and prepared, and forbidding certain products and ingredients all together.

Considering the intricacy of kosher law, you might not have imagined that many Slurpee flavors would meet the strict Kosher Certification guidelines, but they do.

Particularly, Slurpees from kosher-certified brands like Canada Dry, Dr. Pepper, Hawaiian Punch, Squirt, and Sunkist.

Flavors such as Coca-Cola Classic and watermelon Sour Patch are kosher, but so are plenty of funkier picks like sugar-free lite pineapple coconut, lime, Eureka California, and Sprite 6 by LeBron James.

You may be familiar with 7-Eleven Day, otherwise known as "National Slurpee Day", which falls on July 11th.

On this magical day, 7-Elevens across the U.S. hand out free small Slurpees from 11 a.m. to 7 p.m..

But the fun doesn't stop on July 11th.

The chain celebrates the entire week of 7-Eleven Day with promos on drinks, candy, and treats.

A lesser known, equally awesome Slurpee holiday is Bring Your Own Cup Day.

On this day, customers can fill up their own, any-size cup with Slurpee nectar for a buck-fifty.

In the past, people have gone a little wild on BYO Cup day, emerging from 7-Elevens lugging everything from water jugs to kiddie pools filled with Slurpees.

Since then, 7-Eleven has introduced some restrictions.

You can fill any cup of your choice for just a buck-fifty, as long as that cup is safe, clean, water-tight, and can fit through a 10-inch diameter hole.

Still, on BYO Cup Day, you'll see creative Slurpee fans loading up with everything from hollowed-out pineapples to Halloween pails.