I’m sitting in the bar at Melbourne’s Cinema Nova across from a cast member of The Room, the worst film ever made. It’s an inauspicious claim to fame, but Greg Sestero has made his peace with it.

The American actor asks, rhetorically and out of nowhere: “Do I regret it? Do I wish I could erase that from my resume?”

“It’s brought me everything I could have wished for. Had I just ended up being an actor on a soap, I doubt I’d be as fulfilled as I am now. It’s pushed me in different ways.”

Sestero is every bit the straight man we see in the cult film, which, 13 years after its release, continues to sell out theatres the world over.

He’s soft-spoken and clean-cut, and looks like he’s just wandered in from the surf. It’s easy to imagine him in a daytime soap in his Sliding Doors-esque parallel world. Instead, his role in The Room brought him here. He’s in Australia to talk about The Disaster Artist, a movie directed by and starring James Franco, based on Sestero’s book on the bizarre tale behind the 2003 film.

It’s a faithful retelling of Sestero’s side of the story, which is about the awkward bromance between himself and the movie’s creator and accidental star, Tommy Wiseau. Tommy (James Franco) and Greg (played by Franco’s brother Dave) are both struggling actors in Los Angeles. Greg is young, handsome and trepidatious. Tommy is of indeterminate age, bizarre in appearance and alarmingly overconfident. Then Greg is dragged into Tommy’s dream project: to write, direct, produce and star in his own film, despite being dreadful at all of those things.

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In conversations about The Room it’s Wiseau’s scene-chewing performance that gets most of the attention. But the The Room is worthy of more than mocking. It’s a piece of outsider art that perfectly (and accidentally) communicates the psyche of its artist. Wiseau sees himself as a misunderstood, great American genius. But what he creates is an unintentional self-portrait of a frustrated manchild, inarticulately throwing his ego around, drawing a roomful of reluctant collaborators into his wake.

The Disaster Artist is about that unfocused energy. James Franco’s performance channels Wiseau brilliantly, without descending into caricature or mocking farce. (Wiseau has seen the film, and approves of it “99.9 per cent”.)

Sestero has always viewed The Room as a cry for help.

“He was so stifled and misunderstood for so long,” he says of Wiseau.

It worked. The Room has surpassed being just a shit film, and Wiseau and his movie have attained cult status. To the point that Hollywood wanted to make a movie about his movie. Seth Rogen, Sharon Stone, Hannibal Buress, Megan Mullalley and a raft of other comedic actors appear in the film in tribute to the man and his drama gone awry.

After the release of The Room, Wiseau released a comedy. It wasn’t ironically or fascinatingly terrible, it was just bad.

“It’s rough," Sestero. "Any time he’s trying to do comedy it’s not interesting anymore.

“Tommy is mesmerising, in his way. He knows he has a certain power, but he… he can’t see exactly what that is.”

The men are still best friends, with the same "co-dependent friendship" they've had for roughly two decades.

They’ve just finished work on a new dark drama-comedy called Best Friends. It will supposedly be their last collaboration.

Best Friends is the final act,” he says. “The Room is Tommy’s thing, The Disaster Artist is my thing, and Best Friends is us leaving this world in a way we can both be happy with.”

Beyond that he’s still trepidatious. He even asks for my opinion. “Where would you go?” he says. “What would you be interested in seeing from me?”

It’s not a question I can answer for him. But so far, Greg Sestero’s instincts haven’t led him down the wrong path.

The Disaster Artist is now in cinemas.