A little-known Britney Spears concert documentary reveals how fame disturbingly isolated her

• "Stages: Three Days in Mexico" is a little-known Britney Spears concert documentary.
• Focused on the end of Spears' 2002 tour, it captures how trapped and isolated she was by her fame.
• She also navigates rude press and a huge storm that could cancel the final night of her concert.

Every aspect of Britney Spears' life has been analyzed, so it's kind of shocking that the singer has a forgotten concert documentary.

But Judy Hoffman's "Stages: Three Days in Mexico," centered on the Mexico City stop of Spears' Dream Within a Dream tour, has recently found new interest thanks to the #FreeBritney movement, and it's such a compelling watch.

The 2002 tour supported Spears' third album, "Britney," which featured songs including "I'm a Slave 4 U" and "Overprotected."

So why have you probably never seen "Stages: Three Days in Mexico"? You mean, outside the awful title that gives zero indication that it's about Spears? (Even the doc's cover art has Spears' name but doesn't show her face. Talk about burying a movie!)

"Stages" was created as a DVD doc to accompany a Spears photo book. Perhaps that's how Hoffman was able to be a tad more revealing than some higher-profile looks at the pop star. And though the documentary didn't get a TV or theatrical premiere, it's actually a revealing watch of Spears as a sheltered superstar.

You can tell Spears knew she was a prisoner of her own fame

In the movie, we get a glimpse of what tour life was like for Spears, including constant bodyguard protection, press commitments, photo shoots, chatting it up with her hair stylist, and learning about what her love life was destined to be thanks to a visit from a psychic.

What Hoffman also shows, however, is the restrains of stardom. Spears is isolated, rushed from one commitment to another, and the grind seems to be getting to her.

At least three times in this one-hour documentary, the singer talks about being excited to take a vacation once her Mexico City dates are through. Spears talks about wanting to travel to Greece or do other exciting things while on break, though she acknowledges she'll probably just hang out at her mom's house.

It's that self-awareness of her situation - that she literally can't go anywhere in the world without an international incident erupting - that's so fascinating when watching "Stages." Even at 20 years old, Spears knew she was becoming a prisoner of her fame.

Spears had to deal with a misogynist member of the press

The doc also shows the disturbing aspects of life on the road.

Despite a small army watching every inch of the venue where Spears was set to perform, someone was still able to jump a fence to try to catch a closer glimpse of the hit singer. The movie shows the aftermath, with lots of finger-pointing on whom to blame. Spears was pictured unaware of the chaos, taking a nap in her dressing room.

Though the intruder never got close to Spears, the moment illustrates the seemingly constant threats she faces.

Another cringeworthy moment happens during a press conference when Spears got to Mexico City, shown at the movie's opening.

Things got uncomfortable for the star when a reporter asked her to stand up so he could see the outfit she's wearing. Spears obliged, prompting whistles from some in the audience. The reporter then asked her to spin so he could see her backside. She quickly sat back down and told the reporter, "You can see when I leave."

It's just the latest example of an invasive and misogynistic media that has chewed up Spears through her career.

We see the weight of the world put on Spears' shoulders when bad weather jeopardizes the concert

Perhaps the most troubling, yet fascinating, moment comes at the end of the movie when a rainstorm threatened the cancellation of her final show in Mexico City.

As the production manager scrambled while looking at weather reports, Spears was on the phone with her comanager Johnny Wright deciding whether she wanted to continue. In between calls, Spears was barking instructions on where the dancers should be and what songs should be pulled, all while in the makeup chair getting ready for the show. (She would go on to do an abbreviated concert that night.)

It's the most liberating moment of the movie, as it's the only time when Spears looks as if she has control over her universe. No longer is she just being told where to go and what to do.

However, Hoffman (with the skilled cinematography of the legendary documentarian Albert Maysles) also captures in this moment the enormous pressures a then-20-year-old Spears was going through. The weight of the world thrust upon her is telling in the movie's final shot, in which Hoffman freezes, as Spears looks directly into the camera, mimicking a deer in the headlights, as we hear the roaring impatient crowd in the background.

The director could not film Spears drinking, smoking, or carrying non-Pepsi products

Looking back 19 years later on the making of the doc, Hoffman told Vanity Fair that she felt Spears "was made into a commodity fetish."

Hoffman said that's why the documentary had more of a fly-on-the-wall vérité style.

"You just felt her loneliness and sadness, and it was hard to talk to her," Hoffman said. "I just wanted to leave her alone. I felt so sad. I didn't want to be another press person torturing her. I just didn't want to be like the people I saw that she had to encounter all the time."

Hoffman was also required to protect the brand.

She told Vanity Fair that she was not allowed to film Spears smoking or drinking alcohol. Any beverages she drank other than Pepsi, for which Spears was a spokeswoman, were blurred out. Even the phone she's on in the movie was blurred out because it wasn't the brand she had a sponsorship deal with.

"Stages: Three Days in Mexico" is a must-watch for Spears fans and those who are just fascinated by ever-evolving celebrity culture. What also gives it that I have to see this pull is the fact that it's a lost artifact in Spears' career.

Physical copies are hard to come by, but a bootleg version can be found on YouTube. Catch it before it's gone!