In both of the parallel universes of Sliding Doors (1998), Helen (Gwyneth Paltrow) is a Londoner who loses her job and finds out her boyfriend is cheating on her. In one universe, Helen makes her subway train just in time and comes home to catch her boyfriend in the act. In the other, she misses that train. Watching both versions of the story develop made it a notably more interesting effort in the rom-com genre, and more impressively made the group Aqua a two-hit wonder.

1. WRITER/DIRECTOR PETER HOWITT GOT THE IDEA FOR THE MOVIE AFTER ALMOST BEING HIT BY A CAR.

Peter Howitt (a British actor best known for playing Joey Boswell on BBC's Bread) was late in meeting a friend, and innocently walking along London's Charing Cross Road. "I couldn't decide if I should run for the train or first call my mate at a public phone," Howitt recalled. "I impulsively dashed across the street, and was nearly hit by a car, and that brush with death got me thinking. Something inside my head thought, 'That's interesting. What if he had hit me then?' What are the knock-on effects, the domino effects."

2. HOWITT HAD A NERVOUS BREAKDOWN WHILE WRITING THE MOVIE.

Seven years separated that fateful near-death experience and the finished product. In between, there were 20 script rewrites, thousands of pounds of debt, and one nervous breakdown. "All I could do was stay in my flat in Fulham and cry and write the script for Sliding Doors," Howitt revealed. "The worst lasted about three months. Then I slowly began to get better. Now I'm really glad it happened." He also stopped getting his hair cut until he was done with the movie.

3. THE FUNDING FELL THROUGH. THEN SYDNEY POLLACK SAVED IT IN A CHANCE MEETING.

John Hannah (best known then as Matthew from Four Weddings and a Funeral) committed to the film early, then the financing disappeared. Separately, Hannah was meeting with Oscar-winning director/producer Sydney Pollack and mentioned how disappointed he was that Sliding Doors wasn't going to get made. Within seven days, Pollack read the script, found it "really lovely" and "funny," and got the money to get the film made. When producer Philippa Braithwaite called Howitt to give him the good news, he was at a pub, still upset over losing the initial financing.

4. MINNIE DRIVER WAS ORIGINALLY GOING TO PLAY HELEN.

According to Pollack, when Hannah first told him about Sliding Doors, it was set to be made with a $3 million budget and Minnie Driver would be playing the lead. (Pollack ended up doubling the production budget).

5. GILLIAN ANDERSON WANTED TO PLAY HELEN.

In an interview with Movieline, Gillian Anderson said there was one movie role she felt bad about missing out on: Sliding Doors, which she called "a wonderful, very metaphysically oriented concept that just sends chills down my spine."

6. IT WAS SHOT ON LOCATION IN THE LONDON UNDERGROUND.

The subway scenes were shot at Waterloo station on the Waterloo & City Line and at the Fulham Broadway station on the District Line. Filming on location there costs £500 ($719.50 in today's dollars) per hour, unless you have a crew of fewer than five.

7. JOHN HANNAH HAD A HARD TIME PLAYING A HAPPY PERSON.

In a 1998 interview, Hannah claimed that playing James Hammerton in Sliding Doors "was the hardest thing I've ever done. Like in life, it's much easier to be depressed than to be happy. Being happy and smiling naturally on take 18 is really tough. Give me bawling my eyes out any time."

8. THE "SUSPICIOUS GIRL" IS JOHN HANNAH'S WIFE.

Joanna Roth (Rosencrantz & Guildenstern Are Dead, Mary Shelley's Frankenstein) was cast by Peter Howitt. "Peter Howitt held a party before we started filming, so everyone could get to know each other," Hannah said. "Pete, being Pete, said 'There's a wee part in this film for you, Joanna. Do you want it?' It was like everyone in the room was an old mate of Pete and he was making a home movie, saying: 'Do you want to be in it? And you'll get paid for it, too.'"

9. HOWITT GAVE HIMSELF A CAMEO.

He was the long-haired diner who ordered from Helen on her first night as a waitress.

10. THE ROWERS WERE ACTUALLY DRUNK.

Rowers from the Cygnet Rowing Club portrayed James' crewmates. Alan Cox, one of said rowers, recounted Cygnet's final day of filming online prior to the film's release.

And so to the post-race celebration, which was held in the bar of the Blue Anchor at Hammersmith. Here, the hero mounts a table and leads the bibulous multitude in dancing "Father Abraham." It was at this stage that the director made his first big miscalculation. He must have known the old adage about never working with children or animals, but clearly did not understand how oarsmen can share the worst characteristics of both. Having rehearsed the crews in the dance, he departed saying "have a drink to get warmed up" and deposited £30 with the landlord. It took little guile to persuade the bemused bar staff that an open-ended tab was running and, about five rounds later, when the crews were asked to behave as a drunken rabble, no acting skill was required. A precious moment occurred later as an assistant director enquiring after change from the bar bung learned that the bill had run to over £90. To their credit, the management learnt fast; during further work on the bar scene on the third day, only alcohol-free beer was offered.

11. BRIAN MAY OF QUEEN WROTE "ANOTHER WORLD" JUST FOR THE MOVIE.

Howitt asked his "old friend," the guitarist from Queen, to write a song for Sliding Doors. With the script in hand, May wrote his song "kind of overnight." Howitt loved it and said it was "perfect" for the movie. Unfortunately, a record company—not May's—ended up co-financing the production, so the song was dropped from the film's soundtrack. Instead, May used it as the title track for his next solo album.

12. POLLACK SPENT A LOT OF TIME IN THE EDITING ROOM .

"I got very involved in the editing because it was a picture that required precise editing to know where you were all the time and for the audience to be able to find the movement between the A and B stories," Pollack explained. "I felt that Peter needed some help, so I worked pretty hard on that part of it and was able to make a contribution to it just because it was complicated for a director the first time around."

13. UNLIKE MOST OF HER MOVIES, GWYNETH PALTROW LIKED THIS ONE.

"I've always hated my films," Paltrow said at the film's premiere—after appearing in, among other movies, Se7en (1995) and Emma (1996). "But I'm really proud of this one." She said she "couldn't believe how clever" the script was.

14. IT'S SIMILAR TO KRZYSZTOF KIESLOWSKI'S BLIND CHANCE.

Krzysztof Kieslowski's 1981 film was censored and withheld by Polish authorities until 1987. In Blind Chance, a med school dropout named Witek manages to catch a train and becomes a Communist, misses the train and ends up a radical agitator anti-Communist, and misses the train and becomes an apolitical medical student. 

15. HANNAH STOPPED WORRYING ABOUT CATCHING TRAINS AFTER THE MOVIE.

"I don't run for trains any more. If I'm meant to get the train, I'll get it," he claimed. "If I don't, there'll be another one along in a few minutes."