On July 3, 1985, Michael J. Fox created a time travel movie for a whole new generation when he hopped inside a tricked-out DeLorean and zoomed back in the time—with a little help from some stolen plutonium—to ensure his future existence. In celebration of the film’s 35th anniversary, here are a few things you might not have known about Marty, Doc, and Doc's pet chimpanzee.

1. The Back to the Future script was rejected more than 40 times.

Back to the Future may be considered a contemporary classic today, but the initial response to the script hardly predicted how big of a hit it would become. As screenwriter Bob Gale told CNN in 2010:

“The script was rejected over 40 times by every major studio and by some more than once. We'd go back when they changed management. It was always one of two things. It was ‘Well, this is time travel, and those movies don't make any money.’ We got that a lot. We also got, ‘There's a lot of sweetness to this. It's too nice, we want something raunchier like Porky's. Why don't you take it to Disney?"

2. Disney’s studio executives thought Back to the Future was too raunchy.

Lea Thompson and Michael J. Fox in Back to the Future (1985). Universal Pictures Home Entertainment

Ironically, whereas other major studios saw Back to the Future as a sweet, family-friendly picture that would make a perfect fit for Disney, the Mouse House’s executives thought otherwise. After hearing “take it to Disney” enough times, Gale and director Robert Zemeckis decided to do just that. “This was before Michael Eisner went in and reinvented [Disney],” Gale told CNN. “This was the last vestiges of the old Disney family regime. We went in to meet with an executive and he says, ‘Are you guys nuts? Are you insane? We can't make a movie like this. You've got the kid and the mother in his car! It's incest—this is Disney. It's too dirty for us!"

3. One studio thought Back to the Future would work better if it was retitled Space Man From Pluto.

I'm fighting an ulcer due to horrific studio notes on a project I'm about to give up on.

Then, I read this. pic.twitter.com/nob2mt0CDW — Will McCrabb (@mccrabb_will) August 27, 2016

Worried that people would shun a film with the word future in its title, one of the executives Gale and Zemeckis met with suggested that they retitle the film Space Man From Pluto.

4. Steven Spielberg sent his own memo in response to the note about changing the future of Back to the Future.

Nicholas Hunt/Getty Images

In a 2014 interview with ShortList, Bob Gale admitted that he and Robert Zemeckis were at a bit of a loss over what to do with the title change suggestion. “We took the memo to Steven [Spielberg], who told us ‘Don’t worry, I know how to handle him,’ before writing a letter back which said, ‘Hi Sid, thanks for your most humorous memo, we all got a big laugh out of it, keep ‘em coming.’ Steven knew he would too embarrassed to say that he wanted us to take the letter seriously. Luckily nobody questioned the title after that. Without Steven, it could have all been very different."

5. At no point in any of the Back to the Future movies did anyone predict the Florida Marlins would win the 1997 World Series.

Or the 2003 World Series—no matter what any social media posts you’ve seen to the contrary. The rumor has been around since 1997, but as Snopes reports:

“As intriguing as it might be to believe so, the film Back to the Future Part 2, the 1989 sequel to the 1985’s hit Back to the Future, made no prediction, correct or otherwise, about the results of the 1997 World Series. At the beginning of the film, time-travelling scientist Doc Brown takes Marty McFly forward in time to 21 October 2015 in an effort to alter the future and prevent Marty’s (as yet unborn) children from ending up in prison. While in the future year 2015, Marty watches a holographic sports news broadcast announcing that the Chicago Cubs have swept an unnamed Miami team (represented by a gator, not a marlin) to win the World Series. This broadcast inspires Marty to buy a sports almanac and take it back to the past with him so that he can make accurate bets on future sporting events, but the contents of the almanac are not revealed in the film.”

6. Marty McFly and Doc became friends when Marty snuck into his lab as a teen and ended up with a part-time job.

Have you ever wondered how Marty and Doc became friends in the first place? Well, we did—often enough that, in 2011, we posed that very question to Bob Gale, who shared the origin of Marty and Doc's friendship with Mental Floss:

"He snuck into Doc’s lab, and was fascinated by all the cool stuff that was there. When Doc found him there, he was delighted to find that Marty thought he was cool and accepted him for what he was. Both of them were the black sheep in their respective environments. Doc gave Marty a part-time job to help with experiments, tend to the lab, tend to the dog, etc."

7. Slate wasn’t totally convinced that it was Bob Gale who had, in fact, told us about Marty and Doc’s Back to the Future backstory.

When Slate wrote a story questioning whether Bob Gale was actually behind the explanation, the screenwriter very kindly helped prove the story did indeed come from him by sending us this:

8. In the early drafts of Back to the Future, the time machine was made out of an old refrigerator.

Well, sort of an old refrigerator. “Way back in that second draft, it was going to be a ‘time chamber,’ not unlike a refrigerator, and Doc Brown had to carry it on the back of his truck," Gale explained.

9. Doc Brown originally had a pet chimpanzee in Back to the Future.

Sid Sheinberg, the head of Universal, was anti-chimpanzee: "I looked it up," he told Gale, "no movie with a chimpanzee ever made any money."

“We said, what about those Clint Eastwood movies, Every Which Way But Loose and Any Which Way You Can,?” Gale and Zemeckis countered. “He said, ‘No, that was an orangutan.’ So, we have a dog.”

10. Pizza Hut sold Back to the Future Part II promotional sunglasses, a.k.a. “solar shades,” for $1.99.

They were totally ‘80s and pretty sweet. Fortunately, if you missed out on the original 1989 promotion, you can still find a pair on eBay on occasion. Get yours today—just prepare to spend $40 or more.

11. Princess Diana attended the London premiere of Back to the Future Part II in 1985.

No word on what Di thought of the film.

12. Ronald Reagan quoted Back to the Future in his 1986 State of the Union.

It has long been stated that Ronald Reagan was offered the role of Hill Valley's mayor in Back to the Future III, but turned it down. What is known is that the Reagans hosted a screening of the movie at the White House, and both the POTUS and the First Lady were fans of the film. So much so that Reagan even quoted it in his 1986 State of the Union address, stating: "Where we're going, we don't need roads."

13. Tom Wilson, who played Biff, carried around a card that answered every Back to the Future fan’s most frequently asked questions.

Tom Wilson (Biff in Back to the Future) is so sick of answering the same questions, he gives this card to fans: http://t.co/Ynhr2IMC — Letters of Note (@LettersOfNote) May 11, 2012

After 35 years of being asked the same questions about Back to the Future again and again, it makes sense that Tom Wilson—who played bully Biff—might want to streamline the process. So he carried around a card that answered all of the questions he was asked most often.

14. Elijah Wood made his film debut in Back to the Future II.

Elijah Wood’s first big-screen appearance came in 1989, where he played the kid playing the arcade game Wild Gunman in the Cafe 80s.

15. John DeLorean wrote Bob Gale a letter thanking him for Back to the Future.

John DeLorean, the visionary behind the sports car-turned-time travel machine, sent Bob Gale a note of gratitude about featuring his vehicle in the film. It read: “Thank you for keeping my dream alive.”

22. The real Hill Valley High School counts one former president among its alumni.

Whittier High School, a public high school in Whittier, California, played the role of Hill Valley High School in Back to the Future. In real life, it was Richard Nixon's alma mater.

23. Richard Nixon makes an appearance in Back to the Future II.

Universal Pictures Home Entertainment

Look closely at the headlines on the front page of the Hill Valley Telegraph, which reports that Doc Brown has been declared legally insane and committed to a psychiatric institution. Just to the right of that story, you’ll see another story—purportedly from 1985—that reads: “Nixon to Seek Fifth Term; Vows End to Vietnam War by 1985.”

24. The whole Hill Valley Telegraph is worth another look.

As Jonathan Chiat noted in an excellent round-up of the paper's front pages for New York Magazine, "It is unclear why the Telegraph’s editors would devote such extensive space to Biff Tannen gambling coverage."

25. Homer Simpson took a stab at portraying Back to the Future’s Doc Brown.

In the early 1990s, there was a Back to the Future cartoon which featured Dan Castellaneta as the voice of Doc Brown. Castellaneta is best known as the voice of Homer Simpson on The Simpsons.