Back to the Future is a movie that kind of defies logic. It was a sci-fi adventure comedy that featured an eccentric old man having a very trusting and friendly relationship with a teenage boy, who then goes back in time and almost sleeps with his own mother. When you think about it that way, it’s actually quite disturbing.

Nonetheless, the movie was an instant hit. It spawned two sequels, which were filmed at the same time, and became one of the most praised trilogies in movie history. It turned a failing car company into a piece of iconic cinema history. It spawned video games, an animated series, and even a theme park ride and a musical. It also inspired a new generation of people to be creative, something that is obvious when you look at a cartoon like Rick and Morty, which adds a whole new twist to adventures through time and space (on a much more vulgar level).

You may have watched BttF a hundred times, but we bet there are still some things you don’t know about the Robert Zemeckis films. Here are 17 bits of trivia, Easter eggs, and production mishaps that you probably have never heard of before.

17. No One Wanted to Make It

Director Robert Zemeckis and write Bob Gale originally got the idea for BttF by stumbling upon the high school yearbook of Gale’s father and wondering whether they would be friends with their teenage parents. They developed that idea into a movie screenplay and tried to find a studio who would let them make it. They tried and tried and tried again, actually, and failed miserably. The script was rejected over 40 times.

The problem was that the script was too tame to be a lewd adult comedy, but also too risque for family-friendly studios like Disney (remember, the main story line involves a teenage girl wanting to seduce her time-travelling son). Eventually, Universal Studios decided to take a chance on the bizarre story. Thank God for that!

Via Universal Pictures

16. Eric Stoltz Was Marty McFly

If you’re even a casual fan on BttF, you probably already know this one. The movie began production with actor Eric Stoltz playing Marty McFly, despite the director really wanting Family Ties actor Michael J. Fox to take the role. Unfortunately, Fox’s busy filming schedule for his TV show prevented him from taking the job, forcing Zemeckis to settle for Stoltz.

After about five weeks of filming, Zemeckis has fed up. It just wasn’t working the way he envisioned. He pleaded with Family Ties to compromise on a filming schedule so Fox could do both projects, and they relented. Stoltz was promptly fired and Fox began to work double shifts in order to fulfill both obligations.

Via indierevolver.com

15. Did You Notice Billy Zane?

While the main villain in any BttF is Biff Tannen (or one of his relatives, all played by Thomas F. Wilson), there are always a few thugs hanging around willing to take orders from him. If you look carefully, you’ll notice that Billy Zane actually made his film debut by playing Match, one of Biff’s flunkies. Zane would go on to more famous roles in the movies like Dead Calm, The Phantom, and Titanic.

Zane wasn’t the only film debut in BttF. In the second movie, a young Elijah Wood can be seen playing an “antique” arcade game in a retro cafe. When Marty shows off his sharp shooting skills in the Western-themed game, an 8-year-old Wood scoffs at the ancient technology. Wood would shoot to incredible fame when he landed the leading role in the epic Lord of the Rings trilogy, although he was a well-established actor long before he played Frodo Baggins.

Via Universal

14. Spacemen From Pluto

Universal may have taken a chance on the oft-rejected script, but that didn’t mean they were in love with the movie from the start. One executive kept pushing to change the name of the film to Spaceman From Mars, which would tie in to constant jokes about 1985 Marty acting like an alien compared to the standards of 1955. Executive producer Steven Spielberg put an end to the Spaceman From Pluto push by declaring it a very funny joke.

The movie did contain a scene where Marty dresses up like a futuristic spaceman and tortures his teenage dad with Val Halen music in an effort to get him to make a move on Lorraine. The DeLorean DMC-12 was also chosen because its gull-wing doors make it look like a UFO. So while the name of the movie didn’t change, the “Spaceman” themes were still included.

Via Universal

13. Easter Eggs!

Back to the Future contains a lot of cool Easter eggs and a bunch of other not-so-subtle pieces of product placement. After all, Marty calls himself Calvin Klein when he travels back to 1955 since that’s the name Loraine spotted on his designer undies. And that’s just one example. Here are some others:

When Marty first sports the Sports Almanac in the storefront window, there’s also a plush Roger Rabbit doll (a movie that was also directed by Zemeckis). In BttF 2, Marty notices that Jaws 19 is playing at the cinema, complete with terrifying holographic marketing. The director of that fictional shark film? Max Spielberg, the real-life son of Steven. Lastly, one of the pieces of equipment in Doc Brown’s garage is labelled “CRM 114.” That’s a clever nod to famous director Stanley Kubrick, who used the same label on a radio in Doctor Strangelove.

Via Universal

12. There Was Almost a Nuclear Bomb

Replace Eric Stoltz with Michael J. Fox was a costly decision, and the budget had to be trimmed in other places in order to accommodate the switch. One of the biggest changes made was completely removing an atomic bomb blast. That’s right, Doc and Marty were going to somehow travel to 1955 Nevada and use a nuclear bomb test site as a source of power to get the DeLorean back to 1985. Unfortunately, they didn’t really have the time or the money as a result of the Stoltz firing.

So they improvised, and came up with the classic scene where Doc and Marty use the power of a lightning strike to generate the 1.21 gigawatts of energy needed to activate the flux capacitor. All in all, this probably worked out better anyway. It kept the story local to the town of Hill Valley, by using the broken clock tower. It was also very dramatic, as the characters had to get their timing just right in order to send Marty back to 1985.

Via Universal Pictures

11. “Johnny B. Goode” Was An Expensive Song Choice

One of the coolest moments in BttF was when Marty accidently invents Rock n Roll at the Enchantment Under the Sea dance. He finds himself on stage and rips into a cover of Chuck Berry’s classic tune “Johnny B. Goode.” Michael J. Fox actually learned how to play guitar for the scene, but only well enough to look convincing on camera. It also wasn’t really him singing the lyrics.

The problem was that Berry almost didn’t give the film permission to use the song. The entire crew was ready to shoot the scene, but the negotiations were still ongoing. They started making plans to proceed without the famous track. With time running out, Universal upped their offer to a cool $50,000. Berry accepted the deal, and one of the movie’s most memorable scenes was allowed to stay intact.

Via Universal Pictures

10. Why Jennifer Changed Actresses

One of the most obvious changes in the two BttF sequels are that Marty’s girlfriend Jennifer was replaced by a different actress. Claudia Wells took on the role in the original film, but declined to return for the sequels as a result of her mother becoming very sick. She choose to skip BttF 23 to stay at home and help care for her ailing family member.

Elisabeth Shue took over the role of Jennifer in the second movie, but her role was dramatically reduced so that her different appearance wouldn’t confuse the audience. She basically spends the entire movie unconscious while Marty and Doc save the day.

Via Universal Pictures

9. The Time Machine Was Almost a Fridge

The image most commonly associated with BttF is the DeLorean time machine, squealing its tires to reach 88 mph before disappearing into a burst of electrical charges, leaving nothing but a pair of flaming tire tracks behind. It’s an incredible scene every time, and one that cemented the DeLorean as one of the most iconic cars in movie history. However, early drafts of the script had a different time machine in mind. No, not a different vehicle make or model — a refrigerator.

One of the original ideas was a more portable time machine, and one scene had it strapped to a fridge with Marty inside. The plan was to head towards the aforementioned atomic blast in order to get enough energy to send the fridge back in time. Steven Spielberg ended up canning the idea, worried that kids would trap themselves in their own fridges attempting to mimic the movie. Thankfully, a much better idea for the time machine soon emerged.

Via iloveuselessknowledge.com

8. Einstein Was Almost a Chimp

The name of the movie wasn’t the only thing that Universal Pictures execs tried to change, but in this case it turned out to be a great idea. The script originally called for Doc Brown to have a pet chimpanzee named Shemp. A man named Sidney Sheinberg eventually proclaimed that no movie with a chimp ever made money, and convinced everyone to switch out Shemp for a dog named Einstein. Dogs are much more relatable, anyway. A chimp would have been too strange, even for a movie about time travel.

Sheinberg also changed the name of “Professor Brown” to the lovable “Doc Brown.” Thank God for that, because Marty basically calls him “Doc” for the whole movie.

Via Universal Pictures

7. Foreshadowing!

The opening scene of the movie, which features a variety of different clocks (get it, it’s a movie about time travel!?!?!?), actually has a tiny bit of foreshawing. As the camera pans all the various timepieces, there is a photo from the 1922 silent film Safety Last!, depicting star Harold Lloyd hanging from a clockface in one of the movie’s most iconic scenes.

The scene is recreated in the climax of BttF, when Doc Brown hangs from the clockface of the Hill Valley Court House. In both movies, there is a happy ending. Harold Lloyd makes it to the top of the tower and kisses his girl. Doc Brown manages to connect the wires and ensure Marty and the DeLorean get sent back to 1985.

Via Universal Pictures

6. The Man With No Name

In BttF 3Marty finds himself in an 1885 version of Hill Valley. Basically, the whole franchise reverts to a Western as they try to save Doc from being murdered in a gunfight by Buford “Mad Dog” Tannen. Like in the original, Marty runs into the previous generations of his family and can’t give away that he’s actually their great-great-grandson. He calls himself Clint Eastwood, which is fitting since it’s the one name synonymous with great Western flicks.

It’s a great tribute to The Man With No Name, but Universal and Zemeckis had to ask Eastwood permission to use his name. Thankfully, the grizzled Hollywood star saw the humor involved and allowed Marty to borrow his persona for the finale of the BttF trilogy.

Via Universal Pictures

5. Crispin Glover Wasn’t Exactly a Fan

Back to the Future was one of Crispin Glover’s first acting roles, but he quickly earned a reputation as someone who is tough to work with. He was so nervous performing his lines that many of them had to be dubbed over via later recording sessions. Then, after the first movie was a hit, he refused to come back for the sequels. He claims that he didn’t like the ending, which he said rewarded the characters with money instead of having love be enough. However, director Robert Zemeckis says he demanded an outrageous salary and the studio told him to take a hike.

The sequels were made with a different actor wearing a prosthetic mask made to resemble Glover’s face. He didn’t appreciate being replaced in that manner, and promptly sued Universal for using his likeness without permission. They settled for an undisclosed amount of money, but the lawsuit forced the Screen Actors Guild to make changes to their collective bargaining agreement so prevent similar situations in the future.

Via Universal Pictures

4. How Many Pines?

Every time travel movie needs to pay close attention to continuity. After all, most time travel movies are all about the dangers of meddling with the past and how one small alteration can dramatically change the future. So making sure that the stories stay straight between multiple timelines can be a complex task for the writers and director. For the most part, BttF does a pretty good job of this. However, there’s one hilarious example of taking continuity to the extreme.

When Marty travels back to 1955 from the parking lot of the Twin Pines Mall, the DeLorean accidently runs over a pine tree. When he returns to the same Mall (back in 1985) later in the movie, the sign has been changed to read “Lone Pine Mall.” It’s a small, almost unnoticeable detail. It would have cost extra money to have different signs made up for filming, but it shows how much BttF pays attention to tiny details.

Via Universal Pictures

3. It Almost Predicted the Cubs World Series Win

When BttF 2 was originally filmed, the Chicago Cubs weren’t even at the century mark of their epic World Series championship drought. The film still decided to poke fun at their futility by having Marty be amazing that the Cubbies had somehow managed to win the 2015 World Series. In real life, the 2015 Cubs went 97-65 and advanced all the way to the National League Championship Series against the New York Mets, before being swept out of the postseason in just four games. They would improve on that effort the following season, winning the World Series in an epic Game 7 against the Cleveland Indians. So BttF 2 was only a year off.

Oddly enough, the movie version of the Cubs championship has them playing against a baseball team from Miami. Although the Marlins now call Miami home, they didn’t officially become a team until 1993, while the movie was released in 1989. So they also kind of predicted Miami getting an MLB team too.

Via Universal Pictures

2. The Time Machine Was Almost a Ford Mustang

The DeLorean is one of the most iconic vehicles in movie history. And since the company only really produced one model and quickly went bankrupt, the only thing that anyone really knows or remembers about the car is that it was the time machine in a beloved sci-fi trilogy. These days, there is an entire community of people who purchase and restore old DMC-12 models, many including movie add-ons like the Flux Capacitor or the Mr. Fusion Home Energy Reactor. No one has been able to make it fly, though.

The car was picked because the gull-wing doors and stainless steel body made the DeLorean look futuristic. However, Ford offered Universal a bucketload of money if they would change the time machine to a Ford Mustang. Zemeckis considered it, but eventually refused to compromise on the car he thought was perfect for the movie. BttF is probably the only reason anyone even knows what a DeLorean is.

Via Wikipedia

1. Speaking Of Deloreans, There Were Actually Several

Over the course of three movies, the production team used six different versions of the DeLorean. One of them was made completely out of lightweight fiberglass, for any scene that needed the car to fly. Three other versions (dubbed the A, B, and C cars) were used for various shots depending on the year and the level of close detail the shot would need. One was used just shots of the car interior. One final version was actually destroyed at the end of the trilogy when it was demolished by a train.

Only three of the cars used in filming still exist, with two belonging to Universal and one belonging to a private collector. One of the cars used to be on display outside of the Back to the Future ride at Universal Studios Theme Park in Orlando, Florida, but it was put into storage when the ride was converted into a new theme featuring The Simpsons. The DeLorean still comes out on occasion for pictures or special appearances.

Via YouTube