At 92 years old, artist, heiress and socialite Gloria Vanderbilt is still creating: painting, writing and even starring in one of HBO's latest documentaries, Nothing Left Unsaid, which aired on April 9 and is now available for streaming on HBO GO.

Nothing Left Unsaid is a thoughtful retrospective on Vanderbilt's long and noteworthy life. She has enjoyed and endured the spotlight for more than nine decades, arguably longer than any other public figure. She studied visual arts, acted and brought designer denim into mainstream fashion. She's also been the subject of a bitter and high-profile child custody trial and suffered the losses of her father Reginald Vanderbilt, husband Wyatt Cooper and son Carter Cooper.

An old newsreel at the beginning of the film shows Vanderbilt stepping out in public as a child, seemingly intimidated by the crowds her family attracted. "Money isn't everything," the announcer proclaims. It's a sentiment the next roughly hour and a half seems intent on proving.

Vanderbilt makes for an undeniably compelling documentary subject — elusive and slightly aloof even to those closest to her, including her son and documentary co-star Anderson Cooper.

Of course Cooper's role as both interviewer and offspring is ethically debatable. But then again, the term "documentary" is a bit of a misnomer anyway, as Nothing Left Unsaid could more accurately be characterized a video memoir (in fact, there is a book counterpart to the film entitled The Rainbow Comes and Goes: A Mother and Son on Life, Love, and Loss, which was released on April 5).

Cooper's assertion that his mother's life is both more complex and more interesting than the public's perception of it is probably true. And throughout the film, the audience is given unparalleled access to Vanderbilt and certainly a clearer understanding of her life story.

Still, for all the time the two spend chronicling her erratic behavior — over the course of her life she moved from one career to another, one spouse to the next — and pondering her relentless optimism in spite of tragedy — she still waits for a letter from her late father to arrive in the mail, insists her next great love is right around the corner — the reasons for her actions and beliefs nevertheless remain mostly a mystery.

Storytelling shortcomings notwithstanding, Nothing Left Unsaid is a beautiful film, featuring an appropriately haunting music box-style soundtrack and animated paper dolls to aid the narrative.

One isn't likely to walk away with any real revelations about Vanderbilt, but Nothing Left Unsaid taps into a number of universal emotions that ultimately make it worth the watch.