Did Britney Spears really have a nervous breakdown this weekend for the whole world to see?

That was the reaction most people had when they saw photos of the pop star shaving her own head.

But insiders say not so fast.

Less than 24 hours after her act of "shear madness," Spears happily lounged poolside at West Hollywood's chic Mondrian hotel sporting a short blond wig to cover her newly shorn skull.

The star had a green cap over the wig and was wearing a multicolored bikini top and a mismatched bikini bottom, reports E! gossip columnist Marc Malkin.

Though rumors persisted that Spears had "lost it," witnesses at the pool said she seemed to be in good spirits, chatting with her friends and chain-smoking. Her kids were not with her.

"She was definitely having fun with her friends," Malkin said.

Cameras also caught Spears sporting a platinum blond wig at The Roxy in West Hollywood Sunday night.

Video: Click here to see video of Britney wearing a wig

As for the buzz cut, a Las Vegas gossip Web site offers another possible reason for Spears' new do.

Three weeks ago, it says, Spears went to a salon in the Palms hotel and casino in Las Vegas. There, staffers found her hair was so badly damaged from repeated dye jobs, bleachings and extensions that it had broken off and thinned to the point "where bald spots had begun to appear," the site reported.

So she may have clipped it off to start over.

Click here to view photos of Spears cutting her own hair.

Click here to view video of Spears' new do and tattoos.

Spears also may have shaved off her hair in an act of rebellion against her mother, a source told the New York Post on Sunday.

The source, with the Los Angeles-based X17 photo agency that uncovered Spears' haircut at a Los Angeles hair salon Friday night, said Spears and her mom, Lynne, 50, had been feuding over the mother's demand that her 25-year-old daughter clean up her act and settle into motherhood herself.

Last Wednesday, Spears checked into Eric Clapton's Crossroads Centre rehab clinic on the Caribbean island of Antigua — but stayed only 24 hours.

The source said Spears and her mother had been fighting about rehab since she returned to Los Angeles — and the photo agency has pictures to prove it.

So Spears shockingly shaved off her long locks to rebel against her mom, the source said.

Lynne, who lives in Kentwood, La., flew to Tinseltown last week to be with her daughter — and to help take care of Spears' kids, Sean Preston, 18 months, and Jayden James, 5 months.

"Yes, Lynne took a flight to see her a few days ago," Spears' cousin Ernest Spears told The Post Sunday.

Spears strode into Esther's Haircutting Studio in the Tarzana section of Los Angeles on Friday and asked owner Esther Tognozzi to shave her head.

"I tried to talk her out of it. I said, 'Are you sure you're not having a bad day and tomorrow you'll feel differently about it? Why don't we wait a little bit?'" Tognozzi told a cable news network.

"She said 'No, I absolutely want it shaved off now.' Next thing I know, she grabbed the buzzer and she went to the back of my salon and she was shaving off her own hair," Tognozzi said.

When she finished, she declared: "'Oh, my God, I shaved it all off. My mom is going to be upset with me.'"

Then as TV cameras rolled, shutterbugs snapped and onlookers cheered and jeered, Spears put a hood over her hairless head, got into her black SUV and was driven to the Body and Soul Tattoo parlor.

There, she had red-and-pink lips tattooed on her wrist and a black, white and pink cross inked on her lower hip.

Then she got into her SUV and drove off.

There may be one more reason Spears hasn't been herself lately. In the star's hometown of Kentwood, La., her aunt Wanda Bridges told the New York Daily News that Spears had been greatly saddened by the death of her aunt Sandra Bridges Covington, 59, who succumbed to cancer last month and with whom she was very close.

Click here to view photos of Spears cutting her own hair.

Click here to view video of Spears' new do and tattoos.

Get complete coverage in FOXNews.com's Britney Spears Celebrity Center.