The 39-year-old pop icon was the subject of the television documentary that was co-produced with Left/Right Productions and aired on FX in early February.
The show examined her life and career, as well as her well-publicized public meltdown that occurred in 2007.
Since the program debuted, Spears has been relatively silent on the subject, but that changed on Tuesday when she took to Instagram to share her reaction.
"My life has always been very speculated ...watched ... and judged really my whole life !!!" she began in the caption. "For my sanity I need to dance to [Steven Tyler] every night of my life to feel wild and human and alive !!!"
The star added that because she's performed in front of crowds for a great deal of her life, she's always been "exposed" and that "it takes a lot of strength to TRUST the universe with your real vulnerability."
She added that she's "always" been "judged," "insulted" and "embarrassed by the media" -- and still is to this day.
"As the world keeps on turning and life goes on we still remain so fragile and sensitive as people !!!" she added. "I didn't watch the documentary but from what I did see of it I was embarrassed by the light they put me in."
The "Toxic" singer said she "cried for two weeks" -- and still cries at times -- after seeing parts of the doc.
"I do what I can in my own spirituality with myself to try and keep my own joy ... love ... and happiness !!!!" she concluded in the post. "Every day dancing brings me joy !!! I'm not here to be perfect ... perfect is boring ... I'm here to pass on kindness !!!!"
As she often does, the "Crossroads" star paired her statement with a video of her dancing -- this time to Aerosmith's "Crazy."
Reps for the New York Times Company and Left/Right Productions did not immediately respond to Fox News' request for comment.
The documentary renewed interest in what has come to be known as the "Free Britney" movement, which advocates for the star to be released from her conservatorship, which has allowed a guardian -- generally her father Jamie -- to oversee her everyday life and finances. The conservatorship was instilled after her meltdown well over a decade ago.
Timberlake has apologized for his actions toward Spears, as well as to Janet Jackson during their now-infamous wardrobe malfunction during the Super Bowl in 2004.
Just days ago, the pop star's attorney filed a request to remove Jamie as the conservator of her person.