The new Anthony Weiner doc is an incredibly revealing look at his public meltdown

Anthony Weiner watches in horror from his living room as a TV news report shows him flipping off a reporter.

His wife, Huma Abedin, sits in the dining room eating a slice of pizza, trying to ignore it all.

The moment is caught on camera for a documentary about Weiner and his failed New York City mayoral candidacy.

"I can't believe I gave a reporter the finger," Weiner mumbles to himself.

The filmmaker, Josh Kriegman, asks him, "Why are you letting me film this?"

It's one of those moments that make the new movie "Weiner" - which is out Friday and won the grand jury documentary prize this year at the Sundance Film Festival - a joy to watch.

In an era in which people of power attempt to keep everything about their lives hidden behind a veil of orchestrated social-media posts and safe appearances, Weiner allows so much access into his life for the movie that you wonder if the former congressman regrets any of it.

But while clearly a political miscalculation, the movie is perhaps Weiner's self-inflicted penance for past transgressions.

Weiner came to notoriety thanks to the passion he brought to the floor of Congress on issues he appeared to care very deeply about, especially in 2010, when his displeasure with Republicans opposing the 9/11 Health and Compensation Act - which would provide funds for sick 9/11 first responders - went viral.

Less than a year later, Weiner's political career crumbled after he tweeted a sexually explicit photo of himself. After several days of denying he sent it, he admitted to posting the photo. In June 2011 he resigned from Congress.

But America loves a comeback story, and Weiner was ready to be its latest when in 2013 he ran for mayor of New York.

Directors Kreigman and Elyse Steinberg were there with cameras in hand to capture what would become "Weiner." I imagine they sold it to Weiner as a way to show his underdog story. Think of the 2005 documentary "Street Fight," director Marshall Curry's look at the successful campaign of Cory Booker to become mayor of Newark, New Jersey.

Instead, "Weiner" is basically the political equivalent of the 2002 documentary "Lost in La Mancha," in which filmmakers document Terry Gilliam making his passion project "The Man Who Killed Don Quixote" with Johnny Depp, and instead the project is ruined by actor injuries, horrible weather, and fighter jets flying overhead.

But while Gilliam had the universe to blame for his failure, Weiner can only blame himself.

As the campaign for mayor looks to be going strong at the beginning of the movie, a few months into the election, news breaks that Weiner sent explicit photos of himself to a 22-year-old a year after he left Congress, under the alias "Carlos Danger."

You may remember the constant late-night TV jokes about the scandal during the summer of 2013, but reliving it behind the scenes of the campaign and seeing Weiner's personal life with Abedin (who is a close adviser to Democratic presidential frontrunner Hillary Clinton) provide a unique perspective.

Weiner allows cameras to show the damage control that attempts to extinguish the latest scandal. The biggest question: When did he send the photos? As cameras capture, he told most of the press at the beginning of the campaign that he had stopped sending sexual photos of himself after he left Congress.

In one scene, his publicist is reading him questions from a reporter. One asks if he thinks he is a sex addict.

The moments that made me cringe the most were conversations Weiner had with Huma. In some cases, Weiner asked cameras to be tuned off, but there are other times when the cameras are there, such as when they decide what Huma should say at the press conference addressing the latest photo scandal, and if she should continue going to campaign functions. In those instances, Huma says little, but her face and demeanor speak volumes.

In many of these cases, Weiner looks less like an understanding husband and more like a politician seeking votes and needing his supportive wife by his side to do so.

Then there's the conclusion of the movie, which I won't give away, but it's on my top-five all-time documentary endings.

"Weiner" certainly proves that sometimes real life is stranger than fiction. But it also shows what it's like to be on the wrong side of celebrity.

Weiner shrugs that he doesn't know why he's letting Josh film him react to the news report about him giving the finger. But it may be the same reason why, earlier in the movie, he lets Josh film him watching a video (with glee) of his appearance on a political show in which Weiner and the host engage in a screaming match. It seems like Weiner gets a kick out of the attention, good or bad.

The movie suggests the scary notion that many people who crave fame or power simply love it when people are always talking about them. Weiner takes that principle to a shocking level with his transparency in the movie.

But as with his scandals, he can't really cry foul. After all, he brought it on himself.