Daniel Day-Lewis and Paul Dano in There Will Be Blood. Photo: Miramax

Box-office records inevitably get broken and Oscars can go missing; perhaps the surest mark of a great film is how many urban legends spring up in its wake. (Just ask that munchkin.) Paul Thomas Anderson’s There Will Be Blood is only ten years old, but it already has its own defining myth. As the story goes, Daniel Day-Lewis was so committed to the madness of his Method that the young actor who was supposed to play Eli Sunday got freaked out and quit the film — which required Paul Dano, who was already playing Eli’s brother Paul, to step in and take the dual role. It’s one of those anecdotes that makes the rounds in lists like “7 Famous Actors Who Were Genuinely Terrified On Set,” each of them linking to the ones that come before.

As far as anyone can tell, the rumor dates to single line in a New York Times Magazine story from November 2007. Writer Lynn Hirschberg reports that the original Eli had to be replaced a few weeks into production, and after outlining some of the pressures that Day-Lewis has been known to put on his co-stars, she notes that “there are reports that the first actor suffered from intimidation.” Hirschberg also included the official line — that the actor just “wasn’t the right fit,” as Anderson put it — but the hint of behind-the-scenes psychodrama proved to be irresistible gossip.

“There’s something about that story that I understand is super compelling,” says Kel O’Neill, the man who originally played Eli. He chalks up its persistence to the hunger we have for stories about great artists. “It gets at something that we collectively want to believe about Daniel, or anybody who is really good at what they do,” he says. “That they’re somehow remote from us. They’re special and different, and in a way they deserve to be held to a different set of standards, because what they give to the world is so incredible.”

O’Neill is skeptical that, ten years later, there’s anything he can do to correct the record, and he’s probably right. But if you’re curious, here’s what actually happened — at least, as far as O’Neill can remember.

O’Neill didn’t dream of becoming an actor. He describes it as something he fell into; he did some plays as a kid and then just kind of kept doing it. “Acting was like an assumption on my own part about who I was, and what I did,” he says. After supporting roles in XX/XY and Domino, he taped an audition for There Will Be Blood, but didn’t hear anything back for a year.

O’Neill in 2009. Photo: Michael Buckner/Getty Images for CineVegas

After getting the part, he arrived on the West Texas set a few weeks early at Anderson’s instruction: “The idea was to soak up the isolation.” As soon as production began, it was clear that something wasn’t working. “You know,” he says. “You just know.” But it’s hard for him to put his finger on.

“Filmmaking is so alchemical that sometimes certain factors don’t add up,” he says. “Some directors I’ve worked with — who very few people would say are better directors than Paul — just had a way of making me feel comfortable. For some reason, even though every other actor I know had a relationship with Paul that was super positive and where they did their best work, that just didn’t happen with me. I would attribute that primarily to a failure on my side: An actor should, with every ounce of their humanity, be attempting to give the director what he or she wants. And I recall going in and out on whether I could really do that.”

Two or three weeks in, O’Neill saw that he’d been removed from the upcoming shooting schedule. His days were suddenly empty. “I remember a good deal of solitude, thinking a lot about what I was gonna do next,” he says. “I knew that this was a critical juncture in my life and if there were any goals that I had been sublimating to pursue acting, I had to go after those.” His premonition was correct: He was called into a meeting with Anderson and producer JoAnne Sellar, and fired.

He reiterates that his departure had nothing to do with Daniel Day-Lewis. “It wasn’t drinks every night with Daniel on set, but there’s a fundamental decency to the way he comports himself in those environments that gets lost in the shuffle of these rumors,” he says. “After we did our first scene, he came over, shook my hand and said — sort of in character and sort of not — ‘Welcome.’ And that sets a tone where that person isn’t your enemy. I would be cautious now, especially when he’s not going to do this anymore, about making him so mythical that there’s no acknowledgment of the human being there.”

O”Neill acted in a few films after There Will Be Blood, but in retrospect, getting fired was the thing that proved he needed to find something else to do with his life. “There’s a lot of fun to be had in acting, but it’s not a craft I wake up with the desire to do everyday,” he says. “Daniel Day-Lewis, there was no question what that guy was gonna do: He’s 100 percent an actor. He lives and breathes for it. It’s not just about joy, it’s about hands in the muck.”

For O’Neill, that muck turned out to be experimental filmmaking. He spent his late 20s putting himself through an unofficial film school; now he and his wife Eline Jongsma are an award-winning duo who describe themselves as “working at the intersection of documentary film, art, and technology.” They’re currently a month into a yearlong Sundance residency at the Technicolor Experience Center, where they’re making a new piece of virtual-reality cinema.

“I don’t want to be all TED Talk about it and say that ‘failure is actually necessary for success,’” he says. “Because if I look at where I am in my life, I work in a very specific subsection of a very specific subsection of filmmaking. But anybody should be able to identify with failure. If you meet someone who hasn’t experienced failure, you should immediately run away from them.”

Near the end of our interview, I asked O’Neill if the version of There Will Be Blood that was released was much different than the one he saw being filmed. He couldn’t answer that, he said, because he hasn’t seen it.

“After the firing, I stopped watching anything that was made after mid-period John Carpenter,” he says. “The illusion was popped, and if you can’t be lost in the illusion of a movie … It’s like, I could see the craft-service table.”

O”Neill has since thrown aside his self-imposed limitations, and he says he’s sure he’ll see There Will Be Blood eventually. But he hasn’t been able to avoid the film entirely. A few years ago, he walked into a video store that was playing it on the monitors. “I was like, Looks like a good movie.”