Paris Hilton Says Documentary Will Feature Something 'Traumatic' From Childhood That Still Gives Her Nightmares (Video)

Paris Hilton is opening up.

The 39-year-old entrepreneur, who is preparing to release a documentary called This Is Paris this September, made an appearance on Tuesday’s (July 21) episode of Jimmy Kimmel Live!, guest-hosted by Nikki Glaser.

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“No one really knows who I am. Something happened in my childhood that I’ve never talked about with anyone. I still have nightmares about it,” she says in a preview clip from the doc.

People also obtained a preview, and said that she will discuss the mental abuse she faced as a teen at a Utah boarding school.

“I’m excited, but I’m also very nervous, you know, given the topics discussed in this film because it’s things I’ve never talked about before—really personal and traumatic experiences. So, to talk about that publicly is obviously very hard,” she said.

“Obviously, I’m used to being on camera from being on camera for so long But I’ve always been a very naturally shy person. So, I loved just inventing this character and playing that character. And to actually be myself was a completely different experience, but also almost therapeutic in some way where I learned so much about myself that I had no idea of why I am the way I am and now I understand myself so much more.”

Watch Paris Hilton explain what to expect…