When Nick Lachey and Jessica Simpson announced their split in 2005 some fans were shocked that the fairytale romance was over and wanted to know what happened.

It took a few years before Simpson, who went on to date John Mayer and Tony Romo, revealed the real reason why the couple called it quits in her memoir, "Open Book." It seems fame was part of the reason the singers parted ways, as Simpson began to garner more "endorsement deals" that didn't include Lachey. She told ET "there was a little bit of tension."

That tension mixed with a little bit of jealousy and constantly acting as that perfect couple for the cameras eventually led to the fall of their relationship, according to People. Theirs is not the first relationship to end due to one person's career taking off and the other's standing stagnant — Ryan Phillippe and Reese Witherspoon come to mind.

Despite Lachey taking millions of dollars from the "Employee of the Month" actress in the divorce proceedings, Simpson came out of the divorce that much stronger (via Insider). Simpson went on to earn a hefty sum thanks to launching a billion-dollar fashion brand—Jessica Simpson Collection — that includes shoes, clothing, accessories and a home line. She also became a mom to Maxwell, Ace and Birdie, with husband, Eric Johnson (via People).