"Goosebumps" has been in our collective lives for nearly two decades now, beginning with the first R.L. Stine novel in 1992, the many books that have followed, the TV show and the upcoming movie. That's not even to mention the nightmares that the franchise has inspired.

However, with fans all over the world of all ages, it's still pretty hard to know everything there is to know about "Goosebumps." We dug up some facts that we bet you hadn't realized before.

Did you know...

There are seven different "Goosebumps" book series?

SEVEN. The original series, plus "Tales to Give You Goosebumps," "Give Yourself Goosebumps," "Goosebumps Presents," "Goosebumps Series 2000," "Goosebumps Horrorland" and "Goosebumps Most Wanted."

Author R.L. Stine writes the books' titles first, then comes up with a plot.

Start at the beginning, we guess.

It only takes Stine about three weeks to outline and write each "Goosebumps" novel.

In the episode "Strained Peas," the actors who played the lead characters' parents were a real-life couple and the real parents of that actor.

Tyrone Savage brought the whole gang.

Certain actors appeared in multiple parts on different episodes of the "Goosebumps" TV series, and costumes sometimes resurfaced as well.

For example, there's a green fish person costume in "Shocker on Shock Street" that also crops up in the episode "Deep Trouble."

Stine says his very favorite monster is actually...Jellyjam!

Slappys come in all shapes and sizes.

In the TV episodes "Night of the Living Dummy III" and "Bride of the Living Dummy," Slappy is shown both as human-size and baby-size. Guess when you're a haunted object, size is a changeable thing.

Only one character ever appeared in more than one of Stine's "Slappy" books: Jimmy O' James.

There are several changes made from the first "Goosebumps" book, "Welcome to Dead House" when the story was adapted for TV.

For example, in the TV version, it's not a house that turns people into zombies, it's a chemical accident in the town.

Goosebumps themselves are an evolutionary vestige.

Welcome to the thrilling world of the pilomotor reflex, which in animals makes them look bigger to ward off threats. For us humans, we just look kind of...pointy.

Jack Black drew inspiration from "Citizen Kane" to play Stine in the upcoming "Goosebumps" movie.

"He didn't mind that I was doing a much different characterization of him," Black told Biography. "He has got a great sense of humor, so he was fine with the fact that I was portraying him as this anti-social grouch. He understands drama. The necessity for liberties to be taken."

The "R.L." in R.L. Stine stands for Robert Lawrence.

What's in a name, anyway?

In the episode "Shocker on Shock Street," several props from future and past episodes can be seen in the studio.

Say hello to that fish-person again.

R.L. Stine kept at least one strange movie prop.

Apparently there was a dummy built who looks just like him...and he owns it now.

Director Rob Letterman revealed what really scared him: showing off the movie without visual effects for the first time.

"I literally put it up for 300 people, parents and kids, and I was truly scared because I didn’t know if it was going to work," he told Crave. "And this is what was interesting, there was these moments early on in the movie where we had a couple jump scares in there. When those happened the kids screamed, the parents [gasped], and they all started laughing because they got over it!"

Why does he write all these books? Well, Stine's explanation is simple.

Black said that the real-life thing that gives him goosebumps is "the size of the universe."

"Also, the survival of the human species when I think of the inevitable death of every human being," he told Biography. "It would be sweet if we could live all the way to infinity, but we are going to have to build a Death Star because the sun, at some point, is going to engulf the planet."

Starting early could be the key to success: Stine started writing when he was just nine years old.

The original printing of "Night of the Living Dummy" had an error in its summary.

It reads: "Kris decides to get a dummy of her own. She'll show Kris." It should say, "She'll show Lindy"

Before he was a horror writer, Stine was known as "Jovial Bob Stine" and wrote comedy.

He also worked for a celebrity magazine!

In China, "Goosebumps" is translated as "Chicken Skin."

It has a certain ring to it.

"Goosebumps" hits theaters October 16.