When Harry Met Sally: 13 things about the legendary romantic comedy

It was inspired by conversations between two friends, one male and one female, who asked, "Can men and women be just friends?" — and it ended up becoming one of the biggest romantic comedies of all time. Now When Harry Met Sally, which starred Meg Ryan and Billy Crystal, is turning 30.

So who did Rob Reiner originally have in mind for the roles? Who is the woman who famously says, "I'll have what she's having"? And why did Reiner suddenly change the ending?

To celebrate the anniversary, here are 13 fascinating facts about the rom-com classic:

The film was inspired by director Rob Reiner's personal experience of returning to single life after a divorce.

The film was loosely based on Reiner's experience of the post-divorce single life, and his friendship with writer and filmmaker Nora Ephron. "I'd been married for 10 years and I'd been single for 10 years. And during that time when I was single, I kept being in and out of different relationships, and they didn't go so good. And I kept getting confused. How do you make friendships? If you have sex, does that ruin the friendship? All those questions that are brought up in the film, I said, 'This has got to be the basis for something here,'" remembered Reiner in an interview with the A.V. Club.

"So I went to Nora and I told her about it, and she said, 'I like that idea,' and so she interviewed me. She was like a reporter, and I told her all these stories of different things that I had been through. And she wrote this stuff down, and she injected her own experiences."

The pair went on to make another hit rom-com, Sleepless in Seattle.

They had different actors in mind for the roles.

Meg Ryan and Billy Crystal seemed made for the roles, but it turns out that Reiner had been talking with actors Tom Hanks, Richard Dreyfuss and Michael Keaton about taking the part of Harry, and was thinking of Molly Ringwald to play Sally. In the end, he cast his best friend Billy Crystal, who at the time was a complete unknown, and Meg Ryan, who had never played a leading role in a major film.

"Billy was not a movie star at that point, and Meg, people didn't even know. She had done something like D.O.A. and had a small part in Top Gun. Billy was my best friend at the time, so I thought he would be good in this part and I didn't have to worry about the studio because I was the studio—we were financing our own film. It was a tricky thing because he was my best friend, so I had to be sure he was right for it because if it didn't work, it could get really uncomfortable and awkward," he said in an interview with the Daily Beast.

"But I crossed that bridge and we agreed to do it, and then we held auditions and Meg read with Billy. They had instant chemistry and I thought, 'OK, this is great.'"

The between-scene "how me met" stories came from real couples.

Ephron wrote the script over several years — at the same time Reiner was making hit films Stand By Me and The Princess Bride — and when she got tired of writing, she would interview co-workers in the production company. Those interviews, in turn, became the interludes where couples talk about how they met. (The scenes were shot with actors.)

Reiner's mother appears in the scene that many call one of the funniest movie scenes of all time.

In the legendary scene where Sally fakes an orgasm in a diner to prove a point to Harry, a woman sitting at a table nearby quips to the server, "I'll have what she's having." The line was one that Crystal suggested during filming; the woman who delivered it was Reiner's mother Estelle.

"She thought it was hilarious," said Reiner. When Estelle died in 2008 at the age of 94, the New York Times described her as the matriarch of one of the leading families in American comedy, and the person "who delivered one of the most memorably funny lines in movie history."

Reiner also had to, er, show Ryan how it was done.

Ryan was nervous about doing the orgasm scene, especially in front of all of the cast and crew, and Reiner says the first few tries were "very tepid." So he stepped in to demonstrate what he was after.

"I sat down opposite Billy and I acted it out," said Reiner in an interview with the Daily Beast. "I pounded the table again and again going, 'Yes! Yes! Yes!' And when we were done, I turned to Billy and said, 'Uh-oh, I just realized I had a huge orgasm in front of my mother!' Billy jokes about it now, saying it was like being on a date with Sebastian Cabot. And then Meg sat down and did it, and she did it way better than anyone could have done."

That deli, incidentally, is still there.

The orgasm scene was shot at Katz's Delicatessen, which was well-known at the time, but became an international destination after the film. In the film, a sign in the deli reads, "Send a salami to your boy in the Army." (The family deli prides itself on its more than 100-year history, which included sending food to young men fighting in the Second World War.)

According to the New York Times, that sign is still there, but there's another over the infamous table that reads, "Where Harry met Sally... Hope you have what she had!" Be warned, though, that a nostalgic visit to the deli will cost you: a pastrami hot sandwich is $22.45 US, a reuben is $23.45 US, and a "three meat platter" costs $38.95 US. "Generous portions of hand-sliced pastrami, brisket and corned beef," says the menu. "Feeds 3 tourists or one regular customer."

The split-screen scenes were inspired by a classic rom-com.

At several points in the film, Reiner used a split screen to show Harry and Sally talking on the phone — but it turns out the idea wasn't original. The device was inspired by the film Pillow Talk, the 1959 romantic comedy featuring Rock Hudson and Doris Day. In it, the two share a telephone party line (multiple families would share a single phone line) and Hudson — who plays Brad Allen — pretends to be a Texas rancher who woos Jan Morrow (Day) but turns out to be the boy next door. The film was nominated for five Oscars and won for best screenplay.

They had trouble coming up with the title.

Ephron reportedly had a tough time coming up with a title for the screenplay. At first it was called Scenes From a Friendship. Other titles that were considered were Boy Meets Girl, How They Met, and Harry, This Is Sally. Eventually Reiner offered a case of champagne to the person who came up with the winning title.

The film catapulted Harry Connick Jr. to stardom.

Harry Connick Jr.'s star was already on the rise when Reiner asked him to create a soundtrack for the film, but the big band songs — which included standards like It Had To Be You and Let's Call the Whole Thing Off as well as originals — landed the New Orleans crooner his first-ever Grammy for best jazz male vocal performance, catapulting the 22-year-old into the limelight. The album also went double platinum in the U.S., and hit number one on the Billboard Traditional Jazz Chart.

Reiner met his wife while shooting the film, and that changed the ending.

Originally the film was going to have Harry and Sally going their separate ways, but Reiner ended up giving it a more romantic ending after meeting his future wife, photographer Michele Singer, while directing the film. The pair is still together, and they have three children and five grandchildren. The two were originally introduced by cinematographer Barry Sonnenfeld after Reiner heard that Michelle Pfeiffer was getting a divorce and told Sonnenfeld he was going to call her. As Reiner told the Guardian, Sonnenfeld responded, "You're not going to call her, you're going to marry my friend Michele Singer."

Princess Diana attended the U.K. premiere.

Diana, Princess of Wales was still married to Prince Charles when she attended the U.K. premiere of When Harry Met Sally, and she sat next to Crystal. When the orgasm scene was coming up, Reiner looked nervously her way, unsure of how she would react. "But she laughed and laughed!" remembered Reiner in an interview with the Guardian. "And she leaned over to Billy and whispered: 'I'd be laughing a lot more but I know everyone's watching me.'" According to Reiner, she had a copy of the film sent to Kensington Palace so she could watch it with her friends.

The reviews were mostly positive — but not all.

The film still has a 90 per cent approval rating on Rotten Tomatoes, but not everybody was impressed.

The New York Times called the film a Woody Allen ripoff, from its trademark white-on-black credits to its classic jazz-infused score to its obsessive conversations about love, sex and death. ''When Harry Met Sally is the most blatant bow from one director to another since Mr. Allen imitated Ingmar Bergman in Interiors," reads the review, later damning it with faint praise.

"Oddly, Mr. Reiner's best, most inventive films — The Sure Thing and This Is Spinal Tap — have precisely the sly edge and sardonic tone that Harry Met Sally needs. His most recent films, Stand by Me and The Princess Bride, are softer and more nostalgic. And like a sitcom with too much canned laughter, When Harry Met Sally ... is a perfectly pleasant Woody Allen wannabe, full of canned romance."

Reiner was pleasantly surprised that it was a hit.

With summer blockbusters like Batman and Indiana Jones and the Last Crusade hitting theatres, the people behind When Harry Met Sally weren't convinced it would do well — but then it took off, raking in $92.8 million US, well over the $16 million US budget.

"You never know. You make a movie and hopefully you like it, and hopefully other people [do too]," Reiner told People magazine. "You have no idea if it will stand the test of time, and it's kind of cool that it did."

"People love that movie. It's grown on people since it's come out. It's developed into our generation's romantic comedy," said Crystal in an interview. "What's happened with that and The Princess Bride, they're handed down like favourite books."