When a teenage Mischa Barton landed the role of Marissa Cooper on early 2000s teen favourite The O.C., she could not relate to her character.
Marissa was "fast and loose", a rich, privileged teenager who drank and did drugs and had sex. Barton was fresh out of high school, but she had already been acting for years and the long hours left her no time for the typical teenage experience of her peers.
At 17, Barton took on the role feeling like a fraud.
Watch: Mischa Barton talks about Perez Hilton on The Hills: New Beginnings. Post continues below video.
"While everyone at my age was enjoying the carefreeness and untroubled joy of being a teenager, I was working extended hours on set, constantly pressured into meeting needs, demands and goals set by people twice my age or older," she explained in an essay for Harper's Bazaar UK.
"Even being a virgin at the time in that context made me feel like a fraud," Barton wrote, describing her virginity at the time as the "elephant in the room" that she felt she needed to 'get out of the way'.
"I started to really worry that I couldn't play this character if I didn't hurry up and mature a little."
The O.C. became an instant success, and Barton's naivety did not last long.
Now 35, Barton told Harper's Bazaar that her life changed very quickly, with paparazzi following her everywhere and tabloid media interested in all aspects of her life - especially her relationships.
The fame also opened up her social circle, and Barton, still a teenager, found herself pursued by much older men.
"Well, after being pursued by older men in their thirties, I eventually did the deed," she said of having sex for the first time.