Remember When They Dated? 15 Celebrity Couples From 2004!

A decade ago, there were some long-term Hollywood romances we forgot about and some flings we didn't even know about.

There are also some that we remember, but choose to remain in denial about ... ahem … Brad and Jen.

In honor of Throwback Thursday, here are 15 couples from 2004:

1.Usher and Naomi Campbell Their short lived romance ended in and -- like most breakups -- there are two sides to this story. While some say that Usher was "bored" with their relationship, others claim his entourage was very controlling and she didn't like that. Neither of them had anything to say about their relationship or the split.

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2.Justin Timberlake and Cameron Diaz Justin and Cameron met back in at the Kids' Choice Awards and thus began their four year relationship. In 2007, the two split and both claimed it was mutual and they remained good friends. When they came together again at the Bad Teacher premiere in 2011, Cameron said, "Justin and I have always had a good laugh together, and to make a movie where we get to have a laugh together ... there really was no one else who was more perfect for this part."

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3.Ian Somerhalder And Nicky Hilton It's true! Ian and Nicky began their quick relationship at the end of and broke up sometime in the beginning of 2004. We have no idea exactly why they broke up, but we can imagine it's because they have absolutely nothing in common!

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4.Hilary Duff and Joel Madden Hilary was only when she got together with Joel and spent two years with him before they split in 2006. She told Seventeen magazine in 2007 that she felt disrespected that Joel had moved on to Nicole Ritchie so quickly. "I was really happy in my relationship with Joel. I was with him from age 16 to 18. Those are important years. He's my first love, so I'll always care about him. But I definitely feel like a different person now that we broke up. And I DO feel happy," she said. Duff is now the proud mama of son Luca, born in 2012, and the former child star recently announced her split from husband Mike Comrie after three years of marriage.

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5.Lindsay Lohan and Wilmer Valderrama The pair began dating in May , but kept their love quiet for a couple months until she legally turned 18. The couple broke up in November and remained friends. There weren't really any details on why they split, but Dina Lohan told the press that Wilmer was Lindsay's "first love."

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6.Jessica Simpson and Nick Lachey Besides Justin and Britney, Jessica and Nick were the "It" couple of the early s -- and we were crushed when Newlyweds was canceled and they divorced! The couple hasn't been in contact for years and a recent remark from Nick saying that the best part about not being married to Jessica Simpson is her dad Joe shows they may not be on the best of terms. Who can blame him though? Joe Simpson is just about as bad as Dina and Michael Lohan.

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7.Mandy Moore and Zach Braff Mandy and Zach started dating toward the end of and lasted almost two years. In 2006, the couple broke up due to their nine year age gap. She told Elle it just didn't work out between them. "Out of respect to Zach, who I still consider a friend and care about and support, I have nothing bad to say about him."

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8.Britney Spears and Kevin Federline After three months of dating, Britney and Kevin got married on September , 2004. They were married for two years and had two kids before Britney filed for divorce in November of 2006. Britney had a rough couple years following the split, dealing with her divorce, custody issues and a public meltdown, but the pop princess is now said to be friends with Kevin, whose new wife is expecting their second child together.

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9.Nick Carter and Paris Hilton Although they didn't date for long, plenty of drama existed in this celebrity relationship Just a few days after their 2004 breakup, Paris Hilton appeared in public with bruises and didn't deny that they were from Nick. Nick also admitted to cheating on her with Ashlee Simpson and recently opened up about the split in his book. "Paris was the worst person in the world for me to hook up with. [She] fed my worst impulses as far as partying."

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10.Nicole Richie and DJ AM The on-again-off-again couple began dating in and were engaged in 2005. They called off their engagement in early 2006, but were spotted together soon after. They broke up for good in May 2006 and sadly, DJ AM passed away of an accidental drug overdose in 2009, less than one year after surviving a deadly plane crash.

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11.Brad Pitt and Jennifer Aniston Pictures of Brad and Jennifer together still pain us Seriously, look at them, they were perfect. 2004 was a hard year for everyone with the Brad-Angelina scandal. We obviously know why they broke up, but did you know they met on a blind date? Their agents set them up together shortly after Jen's engagement to Tate Donovan ended.

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12.Avril Lavigne and Deryck Whibley Avril began her relationship with Deryck when she was years old and in 2005 Deryck took her to Italy to propose. They stayed together until 2010 when Lavigne filed for divorce. The reason? The couple was too young when they got married and simply grew apart. Fun fact, Deryck took Avril's last name! Last year he finally removed her name.

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13.Kirsten Dunst and Jake Gyllenhaal In , Maggie Gyllenhaal introduced her brother to Kirsten Dunst, and the duo ended up dating for two years. They split in July 2004, and although we don't know the reason why, we do know they did not stay in contact. In 2009, Kirsten told Allure "It would be nice to see him, but we're not good friends."

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14.Heath Ledger and Naomi Watts Heath and Naomi dated for two years and their relationship ended in There was no known reason for the breakup, just that it was an amicable split. Naomi only had amazing things to say about the late actor. She told More, "We had a beautiful relationship, only a couple of years, but he was a man who was completely full of joy, and there was a lot of laughing and affection."

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15.Katie Holmes and Chris Klein The couple met in and ended their engagement in 2005. Very shortly after the breakup, Katie began dating Tom Cruise. Chris later said the couple ended things sooner than everyone thought and he wasn't upset when she called him to tell him about her relationship with Tom. Chris told People, "We found comfort in one another … We had a similar upbringing and we were going through the same experience (in Hollywood). As the teenage craze came to an end, we found that our relationship was changing as well."

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