Entertainment TV Gloria Vanderbilt Shares 'All Our Secrets' with Son Anderson Cooper in Touching Trailer for New Documentary Nothing Left Unsaid: Gloria Vanderbilt and Anderson Cooper premieres on HBO in April By Aurelie Corinthios Published on March 23, 2016 04:35 PM Share Tweet Pin Email Photo: Dimitrios Kambouris/Getty Gloria Vanderbilt is pulling back the curtain on her remarkable life. In a poignant new trailer for Nothing Left Unsaid, her upcoming documentary with son Anderson Cooper, the famous heiress looks back at her life and reflects on her expansive career, fascinating love life and experiences with both tragedy and success. “Growing up, it didn’t really have any reality for me, that whole Vanderbilt side of the family,” Cooper, 48, says in the trailer of his mother, who was born into one of the wealthiest and most famous families in American history. “My mom has lived many different lives and has sort of inhabited many different skins,” he continues. “She’s got this public face, but the reality of her life is so different than what the public face is.” RELATED VIDEO: Anderson Cooper Is a Self-Proclaimed Dork Between intertwining old footage (including previously unseen home videos) and present-day conversations between Vanderbilt and her journalist son, the documentary will explore the life of the famous socialite/designer/artist/actress. “These will be fascinating to read. All our secrets!” Vanderbilt, 92, tells Cooper in the trailer, as the two sift through her archive of letters and photos. “People were so fascinated with this family that apparently had everything,” she says while footage plays of her parents, Reginald Claypoole Vanderbilt and Gloria Morgan Vanderbilt. But Vanderbilt notes, “I never felt that I belonged. I felt like I was an imposter.” “As a young kid, I didn’t know the origins of this sadness that permeated her life,” Cooper says. “She has this drive, and that drive makes it impossible to have a calm existence.” “She’s the last person in my family alive, so I don’t want there to be anything left unsaid between us,” he says. Nothing Left Unsaid premieres April 9 at 9 p.m. ET on HBO.