Justin Timberlake only needed a couple hours to write one of the biggest – and most personal – songs of his career. The pop star revealed he churned out Cry Me A River, the breakup ballad widely believed to be about Britney Spears, extremely quickly.

“I’ve been scorned. I’ve been pissed off. I wrote Cry Me A River in two hours. I didn’t plan on writing it,” Timberlake writes in his new book Hindsight: And All The Things I Can’t See In Front Of Me, according to People.

“The feelings I had were so strong that I had to write it, and I translated my feelings into a form where people could listen and, hopefully, relate to it,” Timberlake continued. “People heard me and they understood it because we’ve all been there.”

Timberlake does not identify the subject of the jaded track in the book. He released the song in Nov 2002, several months after he and Spears called it quits. The hit song features bitter lyrics such as, “The bridges were burned/Now it’s your turn, to cry”.

The source of Timberlake’s pain in the Cry Me A River music video, meanwhile, is a blonde woman who resembles Spears.

Timberlake and the song’s producer, Timbaland, seemed to confirm the song is about Spears during an edition of E! True Hollywood Story that aired in 2011. In the special, Timbaland says Timberlake was furious after seeing Spears speak about him at one of her concerts.

“I was on a phone call that was not the most enjoyable phone call,” Timberlake recalls on the show. “I walked into the studio and (Timbaland) could tell I was visibly angry.”

The song netted Timberlake a Grammy – for Best Male Pop Vocal Performance – in 2004.

Timberlake, 37, began dating actress Jessica Biel in 2007. They have been married since 2012 and they have a three-year-old son named Silas. – New York Daily News/Tribune News Service