There's more to the beloved Californian burger chain than Double-Doubles and their secret and not-so-secret menus. We'll bet even you regulars and superfans don't know some of these.

1. IN-N-OUT WAS CREATED BY A COUPLE OF NEWLYWEDS.

Our founders, Harry and Esther Snyder with their sons, Guy and Rich. A photo posted by In-N-Out Burger (@innout) on Oct 11, 2013 at 11:06am PDT

When it opened in October 1948, In-N-Out was California’s first drive-thru hamburger stand; its founders, Harry and Esther Snyder, were newly married. Harry was known to visit the local Baldwin Park markets every morning to pick up fresh ingredients, and Esther was in charge of the accounting.

2. IN-N-OUT REVOLUTIONIZED FAST FOOD.

In-N-Out is credited as the first chain to have a two-way speaker system for drive-thru ordering. The forward-thinking Harry installed the intercom system in 1948 so that you truly could get "in and out" of his tiny hamburger shack in a hurry. Until that point, drive-ins with carhops who took your order and delivered your food were the norm.

3. THAT YELLOW ARROW WASN'T ALWAYS THERE.

Our original "No Delay" sign. A photo posted by In-N-Out Burger (@innout) on Oct 11, 2013 at 8:43am PDT

The iconic large yellow arrow on the logo first appeared in 1954, replacing the original “No Delay” sign.

4. THEY DIDN'T SERVE FOUNTAIN SODA FOR THE FIRST DECADE.

In 1958, the company added fountain soda to the menu, replacing the bottles they had been selling for a decade. A 12-ounce drink was only 10 cents, and you could actually choose between Coke and Pepsi in the same location!

5. 'X' ACTUALLY MARKS THE SPOT.

In 1972, Harry Snyder introduced the crossed palm trees that stand outside most In-N-Out locations. The idea came from the 1963 movie It’s a Mad, Mad, Mad, Mad World, where the characters hunt for a buried treasure hidden beneath four crossed palms.

6. THE COMPANY HAS A LONG ASSOCIATION WITH DRAG RACING.

From Harry Snyder's 50 percent investment in a new track in Irwindale in 1965 (where his burgers were sold in the concession stands) to Harry and Esther’s only grandchild (and heiress) Lynsi Snyder’s occasional trips out on the track, In-N-Out is a mainstay name around drag racing. According to the National Hot Rod Association, Lynsi has competed in the Super Gas and Top Sportsman Division 7 categories. "I like an adrenaline rush," Lynsi said last year. "My dad took me to the racetrack for the first time when I was 2 or 3. … Anything with a motor, that was in my blood." Lynsi, who has taken auto mechanic classes, often works on her own cars.

7. IN-N-OUT EVEN HAD A CAR.

The company sponsored drag racer Melanie Troxel in 2010.

8. IN-N-OUT HAS ITS OWN "UNIVERSITY."

Established in 1984, the university’s classes aimed to train service staff and managers on how to maintain quality across the board. According to Bloomberg Business, roughly 80 percent of the chain’s store managers rose through the ranks to become career team members.

9. "LOVE WALKS IN" AN IN-N-OUT.

Getty Images

Van Halen’s chart-topping 1986 album 5150 was fueled by In-N-Out burgers. "When I first joined the band, we must have eaten there at least three days a week," Sammy Hagar told Stacy Perman for her 2009 book In-N-Out Burger: A Behind-the-Counter Look at the Fast-Food Chain That Breaks All the Rules. "We were in the studio recording 5150, and we'd send someone to go get food, and we'd talk about sushi or pizza and always end up with In-N-Out."

10. MANY CELEBS LOVE IN-N-OUT.

Speaking of famous fans, high-brow chef Julia Child once told Larry King that In-N-Out was "awfully good," and she reportedly kept a list of store locations in her purse. And, famously, Paris Hilton explained away a DUI arrest in 2006 by telling Ryan Seacrest, "I was just really hungry and I wanted to have an In-N-Out burger!"

11. THEIR JINGLE IS SUPER CATCHY.

You can even get an In-N-Out Burger ringtone!

12. THERE ARE HIDDEN BIBLE VERSES ON THEIR PACKAGING.