Josh Schwartz was just a day shy of 27 when The O.C. premiered on August 5, 2003. A Jewish kid from Providence, Rhode Island, Schwartz's first exposure to the Orange County lifestyle was at the University of Southern California, where he attended film school in the mid-90s. It was there that he met the "species known as the water polo player," and the idea for The O.C. was born.

But no one could have imagined that a hyper self-aware primetime soap starring veteran actor Peter Gallagher, Mischa Barton, and a cast of relative unknowns would become a cultural phenomenon. The O.C. exposed the morally bankrupt lives of the beautiful and wealthy inhabitants of Newport Beach, California -- and it reshaped what a teen soap could be in the process. Not to mention, it's a fashion time capsule for the early aughts, when douchebags still rocked puka shell necklaces and the prettiest girl in school would pair a hip-hugging jean skirt with flip flops and a polo shirt.

Watching The O.C. and weeping along to the sound of Ben Gibbard's mopey cries was a deeply intimate experience. When teenage nerd Seth Cohen (Adam Brody) welcomed teenage delinquent Ryan Atwood (Ben McKenzie) into the family, he invited us in, too: "You're a Cohen now. Welcome to a life of insecurity and paralyzing self-doubt."

For many, the show's incandescent first season remains unparalleled. And yet, during the show's initial ascent into the pop-culture stratosphere, Schwartz had no idea what the fuck he was doing.

"I had never done it before," Schwartz told MTV News at the 2016 ATX Television Festival in Austin earlier this month. "It just happened. There wasn't a lot of time to think about how in-over-our-heads we probably were, but [executive producer] Stephanie [Savage] did tell me when the show got ordered, 'This is going to change your life, and you are going to come out of this experience a different person than you are going into it.' That was the first time I was terrified."

Schwartz met Savage during a general meeting at prolific producer McG's offices in Los Angeles. For a primetime soap devotee like Savage, the idea of a show centered on male friendship instantly struck a chord.

"The serial drama is traditionally a female drama, but the relationships that Josh was most interested in were Seth and Ryan as these brothers and Sandy, Seth, and Ryan as a father and his sons," Savage told MTV News. "I had never seen that before. The idea of a nighttime soap opera that's driven through these male relationships. That was a light-bulb moment for me."

Schwartz's specific view of masculinity was explored through Seth, a character who can best be described as far more Peter Parker than Spider-Man. Originally, the network wasn't so down with having a nerdy, self-deprecating, extremely self-aware kid at the center of the sexy soap.

"Seth Cohen was a bit of a controversial character in the early conception of the show because there was a question of, 'Does this character belong in this genre?'" Savage recalled. "And Josh was really passionate about how that character was going to make the show unique and speak to a different audience."

"He was probably a little more Jewish in the earlier drafts," Schwartz admitted. "I needed Seth. It was like, OK, I can feel my way through this show if there’s this guy commenting on it -- and then [every one of the characters] started commenting on it. Everyone got very self-aware very quickly."

Schwartz was 25 when he sold the idea to Fox; by 26, he had a pilot script and a season order. Savage quickly became his right-hand woman.

"I don't know that [Josh] had time to be scared because [once] we started, we didn't stop," Savage said. After production wrapped on the pilot episode, Fox ordered the series right into production. They were looking for summer programming, which at the time, was unusual. Schwartz and Savage had to hit the ground running.

The first season of The O.C. had 27 episodes, which is pretty much unheard of by today's standards. It's a Herculean feat for any writers' room, especially one with a scrappy, young showrunner in charge. A 27-episode order meant the show tore through a ton of plot -- quickly.

The rise and fall and rebirth of Julie Cooper is one of the The O.C.'s greatest accomplishments, but she did more in one season than most characters do in an entire series. In the pilot, Julie Cooper is the picture-perfect trophy wife: She has the perfect life, the perfect husband, and the most perfect collection of Juicy Couture tracksuits in Newport. By episode 5, she's filing for divorce from Jimmy after it's revealed that the Coopers are broke. Then, in this order, she starts dating real estate tycoon Caleb (Seth's grandfather -- ew) because she's broke, begins an affair with Luke (her daughter's teenage ex-boyfriend) because she's unhappy, and finally, marries Caleb because she's again broke and needs someone to pay for daughter Kaitlin's pony's alopecia treatments.

"We were burning through story so fast," Schwartz said, "that made it really fun for audiences who were watching, but that made it challenging for us when we had to come back in following seasons. But that first season, I think that was part of the fun of the ride. We just went for it."

By the show's fourth episode, it was clear that Schwartz and Savage had created something magical. The episode titled "The Escape" was a defining moment for the series. It not only featured one of the show's most melodramatic moments -- who can't recall exactly where they were and how they felt on the night Barton's Marissa OD'd on painkillers in Tijuana? -- the episode also established what worked: the chemistry.

When we first met Summer Roberts (Rachel Bilson), hands on her hips and sporting frosty blue eyeshadow, we thought, There's no way she's worthy of Seth's unrequited love and worship. That is, until TJ.

"She was a guest star," Schwartz said of Bilson's initial casting. "She had three lines in the pilot, one of which was 'I have to pee. You have to pee?' -- so not any profound monologues for her to deliver. But she was so winning and adorable and brought such a good energy to the show. And she was such a nice contrast to Marissa, in terms of height and temperament.

"We got to the last episode of the summer, which is when all of the kids go to Tijuana, and we really wrote her a bunch of stuff to do that was in that realm of Hepburn-and-Tracy-sparring dialogue with Seth, and she was able to match him dig for dig and joke for joke," he added. "That's when we knew that this girl was sticking with us for the rest of the ride."

As for Summer's favorite expression -- "Ew!" -- that was all Bilson. "We didn't think much about it until we heard Rachel's delivery. That's when we told her that was going to be her 'Whatcha talkin 'bout Willis?' And that was her trademark line."

Of course, Seth pining for Summer was part of the show's DNA from the pilot. He named his boat after her! But after watching Bilson and Brody's burgeoning on-set chemistry, Schwartz knew it was a relationship "that we could really build and sustain."

Unlike the combustible, star-crossed romance between Ryan and Marissa. "Steph likes the epic, broken tragic love stories," Schwartz explained of the The O.C.'s resident Romeo and Juliet. "The laughs were few and far between for them. Tragedy was often lurking right around the corner."

"How hard are they going to fight for this relationship? How many obstacles are people going to throw their way? How many candles is he going to light? We didn't want it to be easy for them," Savage added. (It was anything but.)

"Thank you."

Marissa Cooper, the sad, achingly beautiful girl-next-door, was established in the pilot as a character who Ryan needed to save. Their spark was palpable from the start, when Ryan shared his cigarette with Newport's teen princess in the Cohens' driveway and dropped the most memorable pick-up line in modern TV history.

In that moment, Ryan Atwood -- who, Schwartz said, "probably did pretty well with the ladies back in Chino" -- realized that Marissa Cooper wasn't just another Newport Beach Barbie. However, their driveway meet-cute was nearly ruined by wary network executives.

"That is the last time any characters, or at least teenage characters, smoke a cigarette on broadcast television," Schwartz said. "It was such a battle to get that scene to stay in the show. We had to make sure that at the end of the scene, when Sandy comes down the driveway and breaks them up, he says, 'No smoking in my house!' And they put out the cigarette. That was it; you could never smoke again.

In the end, the performative Hero couldn't save the sun-kissed princess from her own demons, and Marissa's tragic death in the Season 3 finale is still considered the most divisive moment in the show's tumultuous run. Viewers were split. The show's third season is largely considered to be its worst, and a significant part of that ire was directed at Marissa's bleak storyline. Some fans were happy to see her go, while others (mostly teen girls) mourned the loss of a character they felt deserved so much more from the writers. The latter made their displeasure felt the following season, when the show took a serious ratings dive, which led to its eventual cancellation.

It's been nearly a decade since Schwartz and Savage made the decision to kill off Marissa, and it's a fate they still replay in their heads. "There was a whole bunch of reasons that went into that decision, some of which were creative and some of which were practical," Schwartz said. The 39-year-old father feels differently now.

"I'm a dad since we made the show, and that idea of letting her come full circle and have some kind of salvation or closure resonates with me now," he said. "It was hard. It was hard to end the series and not have her be a part of it, too."

"There were weeks and weeks that I spent crying over fan art that had been created," Savage added.

Marissa's death was a tragic end to a tragic season. But even at its weakest, The O.C. had moments of genius. After all, Season 3 introduced one of the show's strongest components: Taylor Townsend, played perfectly by Autumn Reeser. Taylor was a fun addition to a season that was pretty much awful to its core characters.

However, if there's one element of the show that always managed rise to above problematic plotlines, it's the music. For some, The O.C. begins and ends with its indie soundtrack, which was expertly curated by Schwartz, Savage, and music supervisor Alexandra Patsavas. (Occasionally, even the cast would send Patsavas and Schwartz music to listen to.) From the show's very first episode when Schwartz wrote Joseph Arthur's "Honey and the Moon" into the pilot, music became a character on The O.C..

"There was a real conversation at the time of, Is the music in the show going to be Orange County music, which had a really booming music scene at the time, with bands that sounded like Sublime and No Doubt," Schwartz said. "But [we] really wanted the music to feel like an extension of the characters. So the Joseph Arthur song really got you into Ryan's head and made you feel his journey and what he was losing by being taken out of Newport."

"I would send out weekly comps [compilation CDs] with any music that I felt was in the world, which then we discussed at length," Patsavas told MTV News. "If someone responded to a certain band, I'd send Josh or Stephanie or one of the editors more music. Then, I'd pitch for scenes and moments. How are we telling the story? How do these bands and songs and lyrics support the drama?

One of the first songs that I remember sending down to The O.C. on an early comp was 'Dice,' which I felt like was a beautiful song that really had a moment. Of course, it became the New Year's Eve moment in 'The Countdown.'"

Marissa's death, though wildly controversial, was handled beautifully, in part thanks to Imogen Heap's haunting, a cappella cover of Leonard Cohen's "Hallelujah." Both the song and the artist were a significant part of The O.C. by the time Patsavas asked Heap to record the cover for the Season 3 finale. Jeff Buckley's cover of "Hallelujah" accompanies one of the show's defining moments: the final minutes of Season 1. It plays while the camera zooms in on Marissa, lost and alone, trapped in her mother's new Orange County McMansion with a bottle of vodka in her hand. She's a downward spiral waiting to happen. Heap's own profile had been lifted after the Season 2 finale of the series when Marissa shot Trey -- and her song "Hide & Seek" became instantly synonymous with The O.C. (It even spawned a Lonely Island parody on Saturday Night Live.)

There are so many things to love about The O.C. -- the music, the self-aware humor, the witty banter, Anna Stern, the epic romances, Marissa's unforgettable poolside meltdown, and so on -- but what truly made this show special was the intimacy it created between the characters and the viewers. Every week, we were invited over to the Cohens for bagels and schmear. We spent every Chrismukkah around the their kitchen island, listening to Sandy's terrible dad jokes. But we laughed every time.

The O.C. was't just a show; it became part of our lives. And for those four years, Orange County was our home too.