Warner Bros.

Richard Linklater remains one of the most acclaimed indie directors in the business, in no small part because of the enduring appeal of his "Before Trilogy." With the middle chapter in that trilogy, "Before Sunset," turning 15 years old, now is the perfect time to revisit the roller coaster love story of Jesse and Céline and learn more about the making of these three classic romances.

1. Linklater was inspired to write "Before Sunrise" by a similar experience in his own life, where he spent an evening in Philadelphia walking the city and conversing with a woman named Amy Lehrhaupt he met in a toy shop.

2. Sadly, Linklater only learned in 2010 that Lehrhaupt had died in a motorcycle accident prior to the release of "Before Sunrise." "Before Midnight" is dedicated in her memory.

Columbia Pictures

3. While Linklater and co-writer Kim Krizan wrote the screenplay for "Before Sunrise"  in a mere 11 days, it took nine months to choose Ethan Hawke and Julie Delpy as the stars.

4. Jesse and Céline are the only two named characters in "Before Sunset."

Columbia Pictures

5. "Before Sunrise" contains numerous references to author James Joyce and his novel "Ulysses," which also features a protagonist wandering a European city for a night.

6. Linklater originally envisioned "Before Sunset" as a much more ambitious sequel set in multiple cities. But when he couldn't acquire the necessary funding, he opted for a smaller and more intimate approach.

Warner Bros.

7. "Before Sunset" features numerous long take Steadicam shots. The longest of these lasts a full 11 minutes.

8. The older couple who converse with Céline outside her apartment in "Before Sunset" are played by Delpy's parents.

9. Many fans have speculated that Jesse's frayed relationship with his unseen wife in "Before Sunset" is inspired by Hawke's marriage to actress Uma Thurman, as the two got divorced around the time of the film's release. Hawke and Delpy have both acknowledged drawing heavily from their own personal lives when writing their respective characters.

Fox Searchlight Pictures

10. Hawke and Delpy have actually played the Jesse and Céline roles in a total of four films. The two characters also appear in Linklater's 2001 animated film "Waking Life," where they muse about the strange nature of dream time.

11. Because "Waking Life" debuted several years before "Before Sunset," that scene led many fans to assume Jesse and Céline did indeed reunite at the train station. "Before Sunset" proved otherwise, suggesting the "Waking Life" scene never happened or was merely a wistful dream on the part of one of the characters.