Joan Rivers jumped right in when she was asked to be the subject of a documentary.

The 75-year-old comedy icon didn’t think twice about compromising her privacy or watching her vulnerabilities paraded onscreen for our entertainment.

Indeed, Rivers lays herself bare in Ricki Stern and Anne Sundberg’s film Joan Rivers: A Piece of Work, which was shot over 14 rollercoaster months in Rivers’ life.

At a time when subjects like Anna Wintour and Valentino insist on managing their documentary images, Rivers gave the filmmakers total access.

Right from the opening tight close-ups, Rivers shares the anger, frustration, and tears that come with being an ageing comedienne who imagines she is no longer wanted.

“Tell the truth or don’t do it. So much in the public eye is such nonsense and puff. Angeline Jolie and Brad Pitt are such wonderful people and Jennifer Aniston is a wonderful person. And Mel Gibson is such a good father. So much of it is nonsense. It is nonsense; a real documentarian finds the truth. It’s not public relations.”

The truth is that Rivers is on constant high alert, watching the younger comediennes come up while trying to fill her date book. Rivers says it’s that kind of anxiety that makes her funny.

“All comedians have tremendous insecurities and think that the glass is half empty. They’re always worried it’s going to all go away.”

Like many driven and successful artists, one thing makes Rivers completely happy. “Happiness is busy to me. I’m doing a new reality show with my daughter Melissa, like everybody else! It comes in January. ... Total happiness is being creative. I paint a little but I’m not going to spend my life doing it!”

Another thing that apparently makes Rivers happy is being in Canada. “Are you kidding? I love it up there. Canadians are amazing. I want to die in Emerald Lake just above Banff. It’s as good a place as any to go. The Canadian Rockies are amazing, so beautiful. I spit on the American Rockies!”