Britney Spears' mental health came under heavy scrutiny following her performance of Gimme More at the 2007 VMAs - in which the disorientated star sloppily mimed and seemed to forget the dance moves.

But an unearthed clip of the star's dress rehearsals for the now-iconic performance shows Britney pulling off a flawless routine, in stark contrast to the shambolic performance she put in on the night - leaving fans baffled, until now.

In her explosive memoir, The Woman In Me, the star revealed she'd had an extremely awkward backstage run-in with ex Justin Timberlake before her performance, writing: 'It had been a while since I’d seen him. Everything was going great in his world.

'He was at the top of his game in every way, and he had a lot of swagger. I was having a panic attack. I hadn’t rehearsed enough. I hated the way I looked. I knew it was going to be bad.'

Before the run-in Spears looked polished and in great spirits in her dress rehearsals for the performance, at one point donning a large hat and jeans for one run-through - before wearing her famous sparkly lingerie with her hair in a ponytail.

Iconic: Britney Spears ' mental health came under heavy scrutiny following her performance of Gimme More at the 2007 VMAs (right)- but an unearthed clip of the star's dress rehearsals (left)  for the now-iconic performance shows Britney pulling off a flawless routine

Gimme more: Before the run-in with Justin Timberlake, Spears looked polished and in great spirits in her dress rehearsals for the performance (top) compared to the performance (bottom)

Awkward: In her explosive memoir, The Woman In Me, the star revealed she'd had an extremely awkward backstage run-in with ex Justin Timberlake before her performance (pictured 2007)

Spears looked notably more energetic and happy in the dress rehearsal leading fans to comment: 'Damn this rehearsal is better than the final performance ..she obviously show her emotion here ..look at her face she's really into it.'

Another wrote: 'I cannot wait to hear her story behind this performance now that she’s free to speak. Something definitely happened between the rehearsal and the actual performance

Others penned: 'She looked much better in a ponytail and in jeans. I don't know why they finally released her with this hairstyle and clothes. but britney is a legend icon anyway!

'Only britney has iconic rehearsal' and 'The 1st rehearsals looked pretty good . Looks like performance got worsened by the time actual performance.'

After taking to the stage in nothing more than her underwear and sporting extremely visible hair extensions due to shaving her head months before - the singer's big comeback came to a grinding halt.

The performance shocked fans and was universally panned by the public and critics.

She wrote of the moment: 'There was a problem with my costume and with my hair extensions. I hadn’t slept the night before. I was dizzy. It was less than a year since I’d had my second baby in two years but everyone was acting like my not having six-pack abs was offensive,

'I couldn’t believe I was going to have to go out onstage feeling the way I felt.

Britney Spears sports crop top and bikini bottoms during knife dance

Experimenting: Spears donned a large hat in one rehearsal and tied her locks back in another

Looking good: The star showed off her now-famous stage outfit as she worked her way through the routine

Different look: The star also wore jeans and a crop-top for another rehearsal

Difference: Spears looked notably more energetic and happy in the dress rehearsal leading fans to comment: 'Damn this rehearsal is better than the final performance

Gimme More! The star belted out the track in the dress rehearsal (top)

Concern: Spears sparked huge concern with her final performance

Released October 24: Spears' memoir, The Woman In Me, has unleashed a series  of bombshells

The way they were: When Britney began dating wholesome NSYNC star Justin Timberlake in 1999 — fans all over the world saw them as America's golden couple (pictured in 2002)

 'I went out there and did the best I could at that moment in time, which — yes, granted — was far from my best at other times. I could see myself on video throughout the auditorium while I performed; it was like looking at myself in a fun-house mirror.'

Months after her VMA performance in January 2008 Spears was hospitalized at Cedars-Sinai Medical Center after police arriving at her house - after she locked herself in a bathroom with her sons and refused to turn them over to Federline - noticed she appeared to be under the influence.

Federline was given sole legal and physical custody and Spears was placed on a 5150 involuntary psychiatric hold and committed to the psychiatric ward of Ronald Reagan UCLA Medical Center.

Spears would regain visitation rights to her sons in July 2008 and began a return to the spotlight with a documentary and TV appearances.

She would share occasional snapshots of her with the boys over the years – beaming at the camera at a baseball match, celebrating birthday dinners, splashing around in a swimming pool – suggested a tender bond between mother and sons was forged.

But Federline was reportedly given 70 percent custody in 2019.

Kevin now notably has full custody over their two boys and made the decision to move the family from Los Angeles to Hawaii recently.

Taylor Swift and her boyfriend Travis Kelce will both be in Los Angeles this week but the NFL hunk won't be accompanying the singer to the 2024 Golden Globes.

Swift, 34, is expected to attend the 81st annual ceremony at the Beverly Hilton Hotel on Sunday as she's among this year's nominees.

She earned a nomination in the new Cinematic and Box Office Achievement category for her Eras Tour concert film, which has earned over $250million worldwide in less than three months.

On the same night, Kelce, 34, and his team the Kansas City Chiefs will face off against the Los Angeles Chargers at SoFi Stadium, where Swift hosted six sold-out concerts back in August.

Despite the big game taking place before the awards show on CBS, a source told Page Six that Kelce plans to jet back to Kansas City with his teammates right after to prepare for the NFL playoffs.

This means no red carpet and no Golden Globes after-parties for Kelce.

Taylor Swift and her boyfriend Travis Kelce will both be in Los Angeles this week but the NFL hunk won't be accompanying the singer to the 2024 Golden Globes

Swift, 34, is expected to attend the 81st annual ceremony at the Beverly Hilton Hotel on Sunday as she's among this year's nominees; atmosphere at nomination ceremony on December 11

Taylor Swift and Travis Kelce kiss as they ring in New Year

Swift's Eras Tour film may help the superstar nab her first-ever Golden Globe win.

It hit theaters on October 13 and was filmed at one of Swift's LA shows on a $15million budget.

The nearly three-hour movie documents the show from start to finish, allowing fans who couldn't grab tickets a chance to experience the magic.

But Swift is up against some steep competition, including box office hits Barbie and Oppenheimer, in the new award category.

This year's Golden Globe nomination is the fifth of Swift's career as she's snagged four Best Original Song nods over the past decade.

The nominated songs include: Carolina for the film 'Where the Crawdads Sing' (2023), Beautiful Ghost for 'Cats' (2020), Sweeter Than Fiction for 'One Chance' (2014) and Safe & Sound for 'The Hunger Games' (2013).

Swift attended the ceremonies for her first three nominations but was noticeably absent from last year's.

In 2020, she was joined by her now-ex-boyfriend Joe Alwyn but they walked the red carpet separately. The former couple split in early 2023 after six years of dating.

Swift also served as a presenter at the 2019 Golden Globes with Idris Elba.

As for any details about where she may be seated this year, Golden Globes executive producers Glenn Weiss and Ricky Kirshner told Variety that Swift can be 'wherever she wants to be.'

Though they'll be apart on Sunday night, Swift and Kelce did ring in 2024 together at a NYE party in Kansas City, Missouri over the weekend.

She earned a nomination in the new Cinematic and Box Office Achievement category for her Eras Tour film, which has earned over $250million at the worldwide box office in less than three months

On the same night, Kelce, 34, and his team the Kansas City Chiefs will face off against the Los Angeles Chargers at SoFi Stadium, where Swift hosted six sold-out concerts back in August; seen on December 31

Despite the big game taking place before the awards show on CBS, a source told Page Six that Kelce plans to jet back to Kansas City with his teammates right after to prepare for the NFL playoffs

Taylor Swift seen leaving KC after spending holidays with Kelce

Friends shared multiple videos from the night, with a close pal of Kelce's filming the room at midnight, which is when they inadvertently caught the couple kissing as the clock struck midnight.

And another guest filmed themselves amid the celebrations with Travis and Taylor smooching in the background for the entirety of the clip.

They partied the night away after Swift went to cheer Kelce and the Kansas City Chiefs on to victory at Sunday's game against the Cincinnati Bengals.

Swift arrived for the game at Arrowhead Stadium wearing a replica of the same Chiefs jacket that Kelce had arrived in for the Christmas Day NFL game which she was also at. A closer looks shows that she has 'Tay' stitched into the sleeve of her version - a nickname Travis has used for her before.

They have spent plenty of time together as the singer enjoys a break before a another year of touring in 2024.

For Kelce, he is currently in the middle of another relentless NFL season but has at least had two games in Kansas City on Christmas Day and New Year's Eve, allowing more time at home than if the Chiefs had been scheduled to play on the road.

Sunday's win saw the Chiefs wrap up the AFC West, giving Kelce another reason to celebrate after the game.

His team, last year's Super Bowl winners, now round out the regular season next Sunday in Los Angeles against the Chargers before attention will turn sharply to the playoffs.

Swift doesn't resume her Eras Tour until February but if the Chiefs make it to the Super Bowl - in Vegas on February 11 - she might have to make a mad dash from Tokyo, where she will have just played her first shows on 2024, to the west coast to cheer Kelce on.

Swift's Eras Tour film may help the superstar nab her first-ever Golden Globe win; seen at the 2020 ceremony

This year's nomination is the fifth of Swift's career as she's snagged four Best Original Song nods over the past decade; seen at the 2014 ceremony

Swift attended the ceremonies for her first three nominations but was noticeably absent from last year's; seen at the 2013 ceremony

In 2020, she was joined by her now-ex-boyfriend Joe Alwyn but they walked the red carpet separately. The former couple split in early 2023 after six years of dating

Swift also served as a presenter at the 2019 Golden Globes with Idris Elba (pictured)

Taylor Swift and Travis Kelce arrive ahead of Chiefs-Bengals game

Swift this year will then play shows in Australia, Singapore and in the summer, will spend four months touring Europe.

And according to reports last week, Kelce has made some grand plans for Europe - with much of swift's tour coinciding with his football offseason.

The 34-year-old has apparently booked trips to vineyards in Italy and tables for dinners at some of Europe's finest restaurants for the couple to enjoy during her days off.

The Chiefs star could use his time in Britain to plan some adventures of his own, as well.

Recently, on the New Heights podcast that he co-hosts with his brother Jason, Travis suggested that they do live shows in Britain after learning they both have the top selling NFL jerseys there.

The latest that Kelce's season will run to is February 11 with the Super Bowl, with teams then tending to report back for preseason in early August.

The couple went public with their relationship in late September last year when she arrived in Kansas City to cheer him on against the Chicago Bears in September 24. She sat next to his mom, Donna, for the duration of the game.

In her only interview since then, Swift said they had been spending time together up to then and were already a couple.

Though they'll be apart on Sunday night, Swift and Kelce did ring in 2024 together at a NYE party in Kansas City, Missouri on Sunday

Friends shared multiple videos from the night, with a close pal of Kelce's filming the room at midnight, which is when they inadvertently caught the couple kissing as the clock struck midnight

Earlier on NYE, Swift was at Arrowhead Stadium to cheer Travis on in his NFL game

'By the time I went to that first game, we were a couple,' Swift told TIME magazine after they crowned her 2023's Person of the Year.

'I think some people think that they saw our first date at that game? We would never be psychotic enough to hard launch a first date.

'When you say a relationship is public, that means I'm going to see him do what he loves, we're showing up for each other, other people are there and we don't care.

'The opposite of that is you have to go to an extreme amount of effort to make sure no one knows that you're seeing someone. And we're just proud of each other.'