The idea for the movie came from a night Richard Linklater spent walking around Philadelphia with Amy, a woman he met. Contrary to the movie, they stayed in touch for a while, until contact was lost. Linklater never heard from her again, not even when he became a director and Before Sunrise (1995) was released. It was not until 2010 that he found out that Amy had died in a traffic accident before the release of the first film in the trilogy.
Numerous references to James Joyce's novel "Ulysses" can be found in "Before Sunrise." Both take place on June 16th, running into the early hours of June 17th. Both involve a journey around a single city (Dublin/Vienna) and include a visit to a graveyard. Jesse's real name is James (Joyce's first name) and, like Joyce, he spent a long time wandering around the cities of Europe instead of going home.
Richard Linklater left out subtitles but in the opening sequence, the couple on the train is actually arguing in German. The man is reading in his newspaper how 70,000 women are addicted to alcohol. The script translated the squabble as follows: "You're one of them," he says to his wife. She volleys back, saying he's the alcoholic. "I have a reason to do it. I'm married to you!" he retorts.
Unlike Before Sunrise (1995), which did not credit the screenwriting contributions of Hawke and Delpy, the two stars received writing credits for the sequels, and as a result, were nominated for two WGA awards and two Oscars.
[Linklater when asked about improvisation in Before Sunrise (1995)]: "It's a compliment when people think it's [the Sunrise trilogy] improvised, but I don't think anyone could ever understand how much work it is for them [Delpy and Hawke]." Delpy also explained the lack of improvisation. "The truth of these movies is, they are tediously rehearsed, every detail planned, every overlapping line scripted," she told the Chicago Tribune in 2013. "It's so precise that it's almost a joke when people think we are acting off the cuff."
In the scene where Jesse complains about fortune tellers never telling the truth, he quotes almost exactly from a scene in the book "The Circus of Dr. Lao" by Charles G. Finney. In the book the magician Appollonius of Tyana tells a widow that her next day and the day after will be exactly the same as the day before, "a tedious collection of hours". (Page 81, Grey Walls Press edition)
When Richard Linklater first considered casting Ethan Hawke, he thought that the actor was too young for the part. Linklater saw Hawke at a play in New York City and reconsidered after talking to the actor.
In 2012, Hawke told The Guardian he and Delpy performed "controlled improvs" about what Jesse could say to convince her to come with him. Delpy mentioned Celine would only get off the train for someone who was funny and smart. "We finally came up with this idea that I was a time traveler," Hawke said. "She was like, 'Okay, that I would get off the train for.'"
Before Sunrise (1995) only grossed $5 million domestically which is extremely low. However, adjusted for inflation, it becomes the highest-grossing film of the Before trilogy at $10.5 million. While the films were not in high demand at the box office, Linklater, Hawke and Delpy all wanted to make a sequel and did so with Before Sunset (2004)
Richard Linklater is a fan of American singer Kath Bloom, so he used one of her songs, "Come Here" in Before Sunrise (1995). This is the record Jesse and Celine are listening to in the booth. The attention Bloom received from the movie inspired her to release new albums, including 1999's "Come Here: The Florida Years".
At the end of the film it is revealed that Jesse and Celine met on June 16th. This is the same date as in James Joyce's "Ulysses," which follows Leopold Bloom around Dublin for one day. June 16th is celebrated as "Bloomsday."
During a conversation about their first sexual feelings, Jesse explains to Celine that he had an "obsessive relationship with Miss July 1978," and then refers to the playmate as "Crystal." The name of Miss July 1978 was actually Karen Morton, not someone named Crystal.
The landscape and houses seen on the train ride at the beginning of the movie are not typical for the region the train on the route from Budapest to Vienna goes through. Those are probably shots of more western alpine regions of Austria.
The trivia item below may give away important plot points.
Linklater on Jesse and Celine seeing each other again]: "I always said that the movie was a litmus test for how you view romance," he told The New York Times in 2004. "Some people would go: 'It's so clear. They will never get back together.' People were so sure." He said the viewer's interpretation depends on their romantic history. Apparently Delpy, Linklater, and Hawke are romantics-they knew Celine and Jesse would come back together.