Cheating, Justin Timberlake and Colin Farrell: the biggest revelations from Britney's tell-all memoir

When it was announced that Britney Spears would be writing a tell-all memoir, following years of media speculation around her mental health and controversial family conservatorship, people were already gripped.

Then, as Spears and husband Sam Asghari called it quits this summer, during the high season of celebrity break-ups, interest only grew.

It came to a peak last week, when an excerpt of Spears' new memoir, The Woman In Me, was released detailing the end of her relationship with Justin Timberlake in the early 2000s, including the revelation that she had terminated a pregnancy with the *NSYNC star because he didn't want to be a father.

Now, as the memoir hits the shelves worldwide, we have a more complete picture of what Spears has decided to share. Here are the biggest bombshells from her soon-to-be-bestselling book.

While Spears' rise to fame capitalised on her good-girl-gone-bad persona, this transition happened much earlier in her real life. In reality, Spears had a tough upbringing and says she was "usually scared" in her home while growing up, that her parents "fought constantly" and "nothing was ever good enough" for her father, who drank often.

"The saddest part to me was that what I always wanted was a dad who would love me as I was," Spears writes, "somebody who would say 'I just love you. You could do anything right now. I'd still love you with unconditional love'."

By the age of 13, Spears details how she was already smoking, drinking and driving.

When explaining how she got together with ex-boyfriend Justin Timberlake, Britney details how the pair were part of the Mickey Mouse Club in the mid-90s. This was in 1993, when Spears and Timberlake would have been around 12 years old. Describing it as a "boot camp for the entertainment industry", Spears was also club-mates with Christina Aguilera and Ryan Gosling, as well as Timberlake.

Spears reveals that she and Timberlake had their first kiss when they were co-stars on the Mickey Mouse Club, aged around 12 to 13 years old, and attended a sleepover together. She said: "[Once] at a sleepover, we played Truth or Dare, and someone dared Justin to kiss me. A Janet Jackson song was playing in the background as he leaned in and kissed me!"

Finally addressing those cheating rumours for real, Britney admits she did cheat on Justin Timberlake - but only after finding out he had cheated on her multiple times beforehand. But it was Timberlake who portrayed Spears as a cheater, and she addresses her lookalike in the Cry Me A River music video as him publicly "shaming" her for her behaviour. "In the news media, I was described as a harlot who'd broken the heart of America's golden boy," Spears writes. "The truth: I was comatose in Louisiana, and he was happily running around Hollywood."

At one point, Timberlake revealed to the media that he and Spears were sexually active, causing much hoo-hah and ending media speculation that Spears was still a virgin - something she disliked. "Given that I had so many teenage fans, my managers and my press people had long tried to portray me as an eternal virgin - never mind that Justin and I had been living together, and I'd been having sex since I was 14," she writes.

"Was I mad at being 'outed' by him as sexually active? No. To be honest with you, I liked that Justin said that. Why did my managers work so hard to claim I was some kind of young-girl virgin even into my 20s? Whose business was it if I'd had sex or not?"

At one point, Spears remembers seeing more and more older men in the audience of her shows, making her uncomfortable. "Sometimes it would freak me out to see them leering at me like I was some kind of Lolita fantasy for them," she says, "especially when no one could seem to think of me as both sexy and capable, or talented and hot. If I was sexy, they seemed to think I must be stupid. If I was hot, I couldn't possibly be talented."

When Spears was publicly pictured with Colin Farrell in 2003, soon after her breakup with Justin Timberlake, the media went wild. When Spears tracked him down by turning up to the set of his film S.W.A.T, the pair were positioned as the next big celebrity couple. As it turns out, the two were actually only together for two weeks, a period which she describes as more of a "brawl" than a relationship. Spears was still so hurt by her breakup with Timberlake that it was never too serious between her and Farrell, though she says "for a brief moment [...] I did think there could be something there".

As Spears' fame grew to astronomical heights, she began to struggle. She was visited by Madonna, who she says "probably had some intuitive sense of what I was going through". Madonna initiated Spears into Kabbalah, her religion at the time, and Spears went on to have a Hebrew word tattooed at the base of her neck.

"In many ways, Madonna did have a good effect on me," Spears recalls. "She told me I should be sure to take time out for my soul... She modelled a type of strength that I needed to see."

Spears also remembers their decision to kiss at the MTV VMAs in 2003, saying they wanted to create "a moment".

At one point, Spears recalls how she married her childhood friend Jason Alexander for 55 hours in Vegas. "When we got there, another couple was getting married, so we had to wait," she remembers. "Yes - we waited in line to get married."

Then Spears' family found out and things got serious. "They made way too big a deal out of innocent fun. I didn't take it that seriously. I thought a goof-around Vegas wedding was something people might do as a joke. Then my family came and acted like I'd started World War III."

After meeting and marrying dancer Kevin Federline in September 2004, Spears went on to have two children with him, Sean and Jayden in 2005 and 2006. She describes having post-natal depression after their births, saying that "part of [her] became the baby" after giving birth.

"I got a little depressed once I was no longer keeping them safe inside my body. They seemed so vulnerable out in the world of jockeying paparazzi and tabloids. I began to suspect that I was a bit overprotective when I wouldn't let my mom hold Jayden for the first two months... Honestly, as a new mother, it was as if some part of me became the baby."

When Spears reflects on her post-natal depression, she says Federline never witnessed her symptoms. "No one was around to see me spiral - except every paparazzo in America," she writes, describing the pack of photographers following her as "like an army of zombies trying to get in every second".

As well as taking Prozac earlier in her life, Spears also experimented with ADHD drug Adderall during the "party phase" of her life, where she was often pictured alongside Paris Hilton and Lindsay Lohan. When not suffering from ADHD, Adderall has a reverse effect and acts like a stimulant. "It gave me a few hours of feeling less depressed," she says, admitting that she "never had any interest in hard drugs".

Spears broke down in 2007 after her aunt died from cancer and she was kept apart from her sons during a custody battle with Kevin Federline. Then, as the world watched, she shaved her head in a California hair salon as a "f*** you" to the world, because she was "tired" of being the "good girl". "Everyone thought it was hilarious," she writes. "Look how crazy she is! Even my parents acted embarrassed by me. But nobody seemed to understand that I was simply out of my mind with grief. My children had been taken away from me."

After Spears' very public mental health struggles in 2007, she was placed into a conservatorship in 2008, where a court appointed Spears' father, Jamie Spears, to manage her financial and personal affairs on her behalf. She says she "begged the court to appoint literally anyone else - and I mean anyone off the street would have been better - my father was given the job".

After being admitted to hospital "against [her] will", Spears was told that the conservatorship had been filed.

She shares that she was occasionally "smuggled a private phone", but was "always caught". Spears writes: "The sad, honest truth [was that] after everything I had been through, I didn't have a lot of fight left in me".

"It's difficult for me to revisit this darkest chapter of my life and to think about what might have been different if I'd pushed back harder then," she recalls. "I don't at all like to think about that, not whatsoever. I can't afford to, honestly. I've been through too much."

Spears claims she was made to take medication daily and wasn't entrusted with her own personal and financial decisions - but still encouraged to make music and go on tour. "If I was so sick that I couldn't make my own decisions, why did they think it was fine for me to be out there smiling and waving and singing and dancing in a million time zones a week?" she writes. "I'll tell you one good reason. The Circus Tour grossed more than $130m."

She continues: "I became a robot. But not just a robot - a sort of child-robot. I had been so infantilised that I was losing pieces of what made me feel like myself... The conservatorship stripped me of my womanhood, made me into a child."

In response to her conservatorship, Spears did what she could to lash out at her family for taking control of her - usually via her live shows. "I did the moves and I sang the notes, but I didn't put the fire behind it that I had in the past," she says. "Toning down my energy onstage was my own version of a factory slowdown."

At the end of her conservatorship, Spears became pregnant with her partner Sam Asghari, but she miscarried. "I was devastated to have lost the baby," she writes. "Once again, though, I used music to help me gain insight and perspective.

"Every song I sing or dance to lets me tell a different story and gives me a new way to escape. Listening to music on my phone helps me cope with the anger and sadness I face as an adult."

She ends the book by expressing how grateful she is to be "free".

"It's been a while since I felt truly present in my own life, in my own power, in my womanhood," Spears writes. "But I'm here now."