Juliette Danielle, Tommy Wiseau and Greg Sestero star in The

“Nobody knows anything.”

That cautionary maxim attributed to screenwriter William Goldman (“Butch Cassidy and the Sundance Kid”) is among the most oft repeated in Hollywood.

Any seers who claim they can guarantee how a movie will perform are generally lumped into three camps: lunatic, fool or con man. That’s because everyone in the industry understands that deep down, nobody knows anything.

How else to explain why a picture with major stars, huge name recognition and critical acclaim can die miserably at the box office. Or one with no names and no budget can clear $100 million. (See “Paranormal Activity.”)

And how else to explain the bizarre “success” of “The Room.”

For those unfamiliar, “The Room” is a 2003 feature film that is the creation of Tommy Wiseau. As writer, director, star — and undoubtedly financier — Wiseau emits Orson Welles’ ego despite being stuck with Ed Wood’s talent.

It’s hard to get past Wiseau himself, who sports the body of a past-his-prime professional wrestler, the stringy black hair of the Child Catcher from “Chitty Chitty Bang Bang” and a speaking voice once described as “Borat trying to do an impression of Christopher Walken playing a mental patient.”

Initially, his catastrophically inept film went nowhere following a two-week run in Los Angeles. But then clips started to surface a few years later on YouTube. A 21-second excerpt called “Hi, Mark” received hundreds of thousands of hits because of this excellent exchange that finds Johnny (Wiseau) stepping onto the rooftop of his apartment:

Johnny: (to himself) I did not hit her. It’s not true! It’s bull (expletive). I did not hit her! I did NOT. Oh hi, Mark.

Mark: Oh hey Johnny, what’s up?

Johnny: I have a problem with Lisa. She said that I hit her.

Mark: What? Well did you?

Johnny: No, it’s not true. Don’t even ask. What’s new with you?

“The Room” first promoted itself as a drama through marketing materials that called it “a film with the passion of Tennessee Williams” — although the playwright’s name was misspelled as “Tennesee” throughout.

Wiseau has since deviated from his original game plan and is now capitalizing on the fame by claiming it’s a black comedy.

Sure, buddy.

Recently, the project has turned into what can best be described as a cult hit. Sold-out screenings now attract patrons who interact with the screen with “Rocky Horror Picture Show” fervor. They dress as inexplicably tuxedoed characters from the film, toss footballs to each other from a few feet away (the script’s go-to male bonding signifier) and hurl plastic spoons at the screen in honor of the inexplicable photos of silverware displayed in the background. They also exit en masse during an uncomfortably long sex scene between the underdressed Wiseau and his overfed co-star (Juliette Danielle).

A list found at the flick’s official site reveals an impressive array of cities where it’s playing this month.

But the question remains: Why is this bad film receiving so much attention when there is no shortage of bad films being vomited out of Hollywood on any given week?

It could be because of the sheer number of characters who appear and disappear with no explanation. Or because a major character drops the bombshell she has breast cancer, and then this plot point is never referenced again. Or the jarring continuity errors. Or the hypnotically odd performance of the leading man.

But it’s probably because in the film industry, “Nobody knows anything.”

Especially Tommy Wiseau.