Conspiracies, real spiders and potato snow: 25 things you might not know about Home Alone.

In 2023, Macaulay Culkin will turn 43.

Just... let that sink in.

But for many of us, he’ll forever be boisterous eight-year-old Kevin McCallister.

Macaulay Culkin reprised his role as Kevin for a 2018 Google Home commercial and it is everything. Post continues below video.

It’s not really Christmas until you’ve watched Home Alone, the film that made Culkin one of the biggest child stars of all time.

Although you can definitely recite Home Alone word for word (and the franchise is the reason every single one of your friends will caption their December 25 Instagram posts with ‘Merry Christmas, ya filthy animals’), here are 25 things you might not know about the original 1990 classic.

1. The role of Kevin was written specifically for Macaulay Culkin.

Writer John Hughes had Culkin in mind when writing the screenplay and then recommended him to director Chris Columbus. Columbus wanted to see who else was out there, so auditioned more than 100 other kids.

But after reading scenes with Culkin, it was clear he was perfect for the role.

2. And Macaulay wasn't the only Culkin to appear in the film.

Cousin Fuller - yeah, the one who wets the bed - was played by his younger brother Kieran Culkin.

3. The McCallister home is real, and a popular tourist attraction.

Located at 671 Lincoln Avenue in Winnetka, Illinois (one of the wealthiest places in the United States), the kitchen, main staircase and ground-floor of this five-bedroom home were all used for scenes in the movie (the dining room and other rooms were shot on a soundstage).

The house was built in 1921 and features five bedrooms, a fully converted attic, a detached double garage, and a greenhouse.

Kevin's treehouse in the backyard was specifically built for the film and then demolished after filming.

In 2012, the house was sold for US$1.585 million. It's a regular tourist attraction for visitors to Chicago.

4. Old Man Marley wasn't in the original screenplay.

The McCallister's 'scary' neighbour offers one of the most touching storylines of the film, when he confides in Kevin and following his advice, reunites with his estranged son for Christmas Day.

But Marley, played by Roberts Blossom, didn't even exist until director Chris Columbus suggested the film needed to be a little more sentimental.

5. Joe Pesci went all method on set.

Joe Pesci, who played burglar Harry Lyme, did his best to avoid Macaulay Culkin on set in an attempt to make the child actor think he was mean and scary.

That was probably helped by the fact that during rehearsals, Pesci accidentally scared Culkin.

"In the first Home Alone, they hung me up on a coat hook, and Pesci says, ‘I’m gonna bite all your fingers off, one at a time,'" Culkin recalled to Rule Forty Two.

"And during one of the rehearsals, he bit me, and it broke the skin."

6. Joe Pesci wasn't used to being 'family-friendly'.

This makes sense, considering Joe Pesci had just filmed Goodfellas a few months beforehand... But the actor really struggled to watch his language while making the family-friendly film.

He dropped a fair few f-bombs that didn't make the cut - and director Chris Columbus tried to curb his swearing by suggesting he use the word 'fridge' instead.

Only one swear word made the final film... And it wasn't even Pesci's. His co-star Daniel Stern, who played the other burglar Marv, uttered "shit" when attempting to retrieve his shoe through the doggie door.

7. The 'glass' ornaments were actually candy.

It's impossible not to cringe when watching Stern's character Marv step on the ornaments while entering the McCallister home through the window, but the ornaments were actually made of candy.

Stern also wore rubber feet for his barefoot scenes, so despite the absolute horrors that happen to his character's feet, Stern was a-okay.

8. Look, Harry and Marv should definitely have died.

Dr Ryan St Clair of the Weill Cornell Medical College in New York has done some very important work.

Mainly, dissecting the likelihood of Harry and Marv surviving the onslaught of pain Kevin throws at them.

For example, of the iron to the face Marv experiences: "Let's estimate the distance from the first floor to the basement at 15 feet, and assume the steam iron weighs 4 pounds. And note that the iron strikes Marv squarely in the mid-face. This is a serious impact, with enough force to fracture the bones surrounding the eyes. This is also known as a 'blowout fracture,' and can lead to serious disfigurement and debilitating double vision if not repaired properly," Dr St Clair said.

He also said the burning hot doorknob, which is visibly glowing red, is "not quite hot enough to cause Harry's hand to burst into flames, but it is not that far off," and the blowtorch to the scalp would likely cause "the skin and bone tissue on Harry's skull [to] be so damaged and rotted that his skull bone is essentially dying and will likely require a transplant."

Both Harry and Marv also survived a paint can to the face, which Dr St Clair said would've likely caused facial fractures, but were finally - finally - taken out by a shovel to the back of the head.

Legit.

9. There's a conspiracy theory that Elvis... yes, Elvis Presley is in the film.

There is a legend that Elvis Presley (who died in 1977) makes a cameo in this movie.

As the conspiracy goes, many believe the heavily bearded man standing in the background of the scene where Mrs McCallister is shouting at the airport desk clerk (just before she meets John Candy) is Elvis.

10. The tarantula was real.

Ick. Daniel Stern told The Hollywood Reporter there was both a rubber and a real tarantula on set.

"They told me [the tarantula] was real nice and showed it walking across the trainer's arm … everyone seemed cool with it, so I just had them put the friggin' tarantula on my face."

So uh, his scream was also real.

"I asked if [screaming] would spook the spider, but I guess tarantulas can't hear," Stern said. "Again, I was committed fully to that movie... I wanted to hit a home run in every scene."

11. Macaulay Culkin's stunt double was a 30-year-old short man.

Kevin got up to a lot of dangerous shenanigans in Home Alone, so it makes sense a stuntman was brought in ensure Macaulay Culkin wasn't faced with anything too risky.

His name was Larry Nicholas, he was 30 at the time, and he’s the one you see zip-lining to the treehouse and falling off Buzz’s shelves.

12. The van was actually pulling away.

There's a scene where Marv and Harry have to slam on their van's brakes to avoid hitting Kevin. That seems pretty dangerous to film, but it was actually shot with the van pulling away from the child, and then reversed in editing. Clever.

13. John Hughes went to great lengths to make it believable.

Writer John Hughes was worried that mothers would never believe a family could forget one of their kids, so he made sure to fill in every possible logic hole.

An example? When Kevin attacks Buzz and spills milk all over the counter, Peter tries to clean up the spill to save the passports and tickets. As he throws away the mess, he accidentally throws a plane ticket with Kevin's name on it away too. That accounts for why they weren’t tipped off to Kevin’s absence by an unclaimed ticket.

14. Buzz's girlfriend is actually the art director's son.

Chris Columbus thought using a young girl’s photo was too mean (because Kevin responds to the photo by saying "woof"), so instead the art director's son dressed up as a girl.

15. The film Kevin watches isn't real.

The footage was specially created for the film (and was actually the first thing shot).

It was called Angels with Filthy Souls. In Home Alone 2, Kevin watches the sequel titled Angels with Even Filthier Souls.

16. Many of the actors weren't convinced the film would be successful.

During an interview with Alec Baldwin on Baldwin's podcast, Chris Columbus said John Heard (who played Kevin's dad Mr McCallister) was unhappy about working on the film and believed it was going to be bad. Once he saw the finished product and noticed its box office success, Heard apologised.

And according to IMDb, both Joe Pesci and Daniel Stern felt indifferent about the movie's potential during shooting, so they intentionally gave over-the-top performances, neither one of them believing the film would become a massive success.

17. No Macaulay Culkins were harmed in the making of this film.

The crew went to great lengths to keep Culkin safe... Even lying on the floor on both sides of the bed Kevin jumps up and down on while eating popcorn, instructed to catch him if he accidentally fell off.

18. High carb snow.

At the end of the movie where it snows outside Kevin's house, the snow was actually mashed potato flakes. Yum.

19. The Playboy magazine was tampered with.

The pages on the Playboy magazine Kevin looks through in Buzz's room were taped together so Macaulay Culkin wouldn't see any nudity.

20. Test audiences wanted more Kevin.

An original cut of the movie had more scenes of the McCallisters in France, but test audiences wanted to get back to Kevin's shenanigans at home in Chicago.

21. John Candy improvised his lines.

John Candy, who was one of the biggest stars at the time, only had one free day in his schedule, so he filmed all his scenes as Gus Polinski in a marathon 23-hour session.

He was also one of the only ones allowed to go off-script. That story about leaving his son at a funeral home was entirely improvised.

22. The festive set.

To make the film feel extra Christmassy, the colours red and green were used throughout the movie subtly in almost every scene. Furniture, clothing, food packaging, wallpaper - next time you watch it, take note of how festive it all looks.

23. Macaulay Culkin's limited hours.

Child labour laws meant Macaulay Culkin was only allowed to work on set for five hours each day, so his scenes had to be carefully mapped out. A lot of the filming took place overnight, so director Chris Columbus would step in and fill Culkin's place while filming with other characters.

24. They had to rework the filming schedule because of... golf.

Joe Pesci took issue with his 7am call time, refusing to be on set that early because he wanted to play nine holes of golf before he started work.

The Oscar-winner ultimately got what he wanted and call times were pushed back to 9am, meaning he had enough time to fit in his rounds before reporting to set.

25. Clever camera work.

Many of the shots that focus on Kevin in the beginning of the movie are filmed from above his head, making him seem small and helpless. At the end of the film, Kevin is mostly shot from below, making him seem taller and more confident.

And well, he had just survived days at home alone and protected his home from very persistent burglars, so he earned that. Go Kevin.

Feature image: 20th Century Fox.