Love her or hate her, you can’t deny that Joan Rivers has shown amazing staying power in the fickle world of show business. I was never a fan or Rivers or her comedy, but the new documentary Joan Rivers: A Piece of Work got such good reviews that I thought I’d check it out.

I’m glad I did. The film was fascinating, funny and offered major insight into what it takes to survive for 50-plus years in Hollywood — one of the toughest career paths there is. Here are some of my takeaways:

Persevere, persevere, persevere. From tremendous career highs (substituting regularly for Johnny Carson on The Tonight Show) to devastating lows (being blackballed by Carson when she leaves to host her own show, which ultimately fails), Rivers never, ever, ever, ever, ever gives up. I’m not sure many of us could handle the many rejections, public humiliations and personal and professional traumas Rivers endured, but every time she faces a challenge she dusts herself off and gets right back to work.

Do what you love. Perhaps perseverance is easier when you are in love with what you do for a living. According to Rivers, she knew her entire life that she wanted to be in show business, even describing it as a “calling.” While Rivers’ passion borders on compulsion, I was still inspired by her absolute love of performing, the deep effort she puts into it and the sheer joy she feels on stage.

Be flexible. When Rivers couldn’t get a comedy gig to save her life, she turned to her passion for collecting jewelry and started selling on QVC. When she stopped getting big gigs in Las Vegas and New York City, she hopped on planes to Alaska and the Midwest to perform anywhere she could. While I’m not sure Rivers’ proclamation “I’ll do anything! I’ll wear a diaper!” is the best career plan, it’s a good reminder not to be too picky when you really need work.

Let go. This is a lesson I learned from the film because Rivers never seems to learn it. Although Joan Rivers is a model of hard work and perseverance and passion, she also holds onto a lot of bitterness from past hurts and slights. It’s painful to watch her resentment at times, and serves as a reminder that anger at other people is ultimately far more damaging to you than to the people you’re angry at.

Did you see Joan Rivers: A Piece of Work? If so, what did you think? Please share in the comments!