China Forbes is best known as the singer with Pink Martini. But since the movie Infinitely Polar Bear—written and directed by her sister Maya Forbes—hit cinemas this summer, her life story has caught the public imagination in a whole new way. The film—starring Mark Ruffalo (playing Cameron Stuart, a stand-in for their father Cam Forbes), Zoe Saldana, and the director's daughter Imogene Wolodarsky as her own mother, Maya—tells the story of two young girls left in the care of their father, who suffers from bipolar disorder, while their mother goes off to study.

It's a personal and largely autobiographical film, laying out the childhood of Maya and her sister in all its messy detail. We spoke to China Forbes about the experience of seeing her family life play out in frames. 

How did you feel when you learned your sister was going to write a movie about your childhood?

I was really excited. I grew up feeling ashamed about so many things in my life. I felt: “I’m biracial, but people think I’m white, but my mom says I’m black, but am I really black?” It was really confusing and there wasn’t Barack Obama and Mariah Carey to be my biracial role models when I was eight years old. So I thought, “I don’t really know what I am, I’m just me, but I don’t want to talk about it or reveal it, and my dad has bipolar disorder and I don’t really want to talk about that, and we live in squalor and I don’t really want to talk about that.”

I felt all of this shame, and now I don’t feel shame about any of it. In writing this movie my sister was going to put it out for all to see, which was such a relief. I could finally say, “This is what it looked like and this is where I come from and this is who I am. And I don’t have to try to explain it to people any more.” All my friends that I’ve tried to explain it to, they had no idea until they saw the movie what my life was really like. So it’s this amazing gift that I have this example to show people, to explain me. 

Did it feel true to your recollection of that period in your life?  

When I watched it at Sundance with my sister for the first time after it was completed, I was just beaming up at the screen and crying, thinking, “This is my photo album come to life. I get to look at this and see my childhood again.” And I do think she nailed it. There are a couple of little details where I think “I’m the one who did that not you!” or “My friend did that, not me!” She took a lot of details that were real and that we’ve laughed about for years and attributed them to different characters just to make a story, but it’s all real.

Did you have any involvement as she crafted the script? Did she look to you for input? 

Yes, definitely in very small ways. I read the script and I gave notes and she would ask me about things that she couldn’t remember and I would give her my memory. So yes, we’re always very collaborative, but she did it all. 

Though the portraits of your parents are very positive, despite the struggles they clearly faced, some people have been less impressed by your great grandmother—a wealthy, elderly woman who won't give her grandson the money he requests for his children's education—as she is portrayed in the movie.

My great grandmother was very wealthy. She was very old and she did help us, she paid my dad’s rent and she gave us money but I don’t think she understood the importance of seeking and paying for a good education, because in her generation they were just educated automatically, their governess taught them! So it was such a different mindset... She really loved us, but she was from two generations before us, and very proper. Also, there was the hope that my dad would pull himself up by his bootstraps, and a reluctance to cripple him further by paying for his entire life. She did not understand his illness. 

The illness in question is bipolar disorder, characterized by episodes of mania and bouts of severe depression, and very much at the heart of Infinitely Polar Bear, which gets its title from Cam Forbes's own moniker for his illness. While its negative impacts on family life are never elided, the movie holds back judgment, creating a complex portrait of life with bipolar disorder that reveals all the toll and triumph that comes with it.  

I always say I grew up in the great depression, the depression of my dad. When I was young I didn’t know that’s what it was—the inertia, not having a plan, not having a schedule, and lying on the couch. But then in the manic energy there was a lot of picking wild mushrooms and charging through the forest, a creative whirlwind. That’s what it was like growing up. I think my sister captured that really well. I think it’s really important for people to see the gifts of bipolar disorder and not merely the sad and difficult parts. 

What would you want people to take away from your sister's depiction of the illness, and from your experience of it?

To not be afraid of people with bipolar disorder, and to learn from them because they’re some of the most interesting people you’ll ever meet. Because when you’re manic, you’re brilliant. Your brain is so much faster than everybody else’s, and you have so many ideas. A lot of people are repelled by it because there’s so much energy that comes with it and you just want to run from it, but if you can not run from it and just observe it, it’s so interesting.

 Do you feel that having the kind of parents you did helped set you on the path to becoming an artist?

Both my mother and father were always really creative. Everything was homemade at our house. My mom baked from scratch, we made our dolls from scratch and we sewed our curtains, it was all incredibly handmade and creative from when we were very, very young. They also just let us be really free. We were never in a box or put on a track that someone proscribed for us. We dictated our interests and we followed them. It was so open, and I think that’s really a gift, and my sister and I are both artists because of it. 

Was it in any way upsetting to watch this movie? Though there are so many happy and positive scenes, there are also moments of real struggle and sadness.

Definitely. I think the most amazing scene in the movie is the scene near the beginning when my father is in the mental hospital and he comes shuffling out with some flowers. That made me cry when I first saw it. It was so well done and so real and so familiar and so sad. And it’s upsetting to watch my mom struggle, to think that she did all of that work at business school and then would take the train home at the weekend to see us and clean the apartment. And my dad just being on his own with these kids and having no adults around very much, and how hard that must have been.

But one thing that was great about watching the movie for me is that as much as I’ve worked through my sadness about my mom leaving when I was eight and my dad’s illness, until I saw the movie it wasn’t crystal clear to me that there really was no other way for it to turn out. Because my mom was not going to be someone who was a secretary all her life—she is a force of nature and she needed to have a career and she needed to send us to good schools. These are things she really wanted to do, and she had to take the opportunities that came to her because she didn’t have that many other opportunities. And my dad needed us to stay with him. We couldn’t have gone with my mom to New York, and we couldn’t have held my mom back from having a career, and in the end we had all these years with my dad that were incredible. He died really young, at 59, so I feel so lucky that I had that time with him and now I have time with my mom who is still healthy and going strong.

I’m an optimist, so I see that in the end it was all meant to be, it came full circle and it’s a package that works. With a bow on it. I put the bow on it because I can’t help it!

How does it feel to have Hollywood stars play your family members?

Well when it’s Zoe Saldana everybody’s happy about it! Then Mark Ruffalo—who is such a great actor and who I’ve always loved, but who is not who I would have thought of for the role because he doesn’t look anything like my dad— brought so much nuance and range to this role that he’s so convincing, and in the end I’m finding myself watching the movie and trying to superimpose my dad’s face on him.

You wrote a song specifically for the movie.  How did that come about?

The minute my sister said she was making the movie I said: “I’m writing the song for the movie.” When it came time, she said “I want you to write a song about a train”. Then I went on tour to London and brought my son's toy ukulele and taught myself some chords. My cousin lives there, on Hampstead Heath, and she would tell me, “Take this train to the Northern Line.” Whenever she told me that I would think, “The Northern Line! That sounds so poetic!” So I wrote this song called The Northern Line about sisters and parents and family and riding trains and coming home and mania and depression and all of it just kind of poured out.

Though it’s a very personal story, the movie has things to say on some political and social subjects too...

The movie makes a big statement about the state of education in our country. My mom wouldn’t have had to do what she did if there had been decent schools in our neighborhood. We couldn’t afford to live in a fancy neighborhood and the school in our neighborhood was terrible, and that’s sad. The film is not dissing public school, it’s dissing the state of public school.

Now that it’s out there, how does your mother feel about the movie?

She loves it, she’s so proud of both of her daughters. She loves the way she is portrayed, and of course Zoe Saldana and the good outfits! She's thrilled! 

What about your dad? Do you think it’s been a positive thing for your father's memory?

One thing that’s so nice for me, is that I always felt like my dad was this amazing person with all this charisma but he never had any glory in his life of any kind, he didn’t have any recognition for anything really, other than from us for being a great dad. But now people can watch the movie and say, "What a cool character, I wish I could know that guy." I think people really appreciate him, and that makes me happy. It’s his moment to shine, as himself, with all of his flaws. 

Infinitely Polar Bear is currently playing at Regal Cinemas Fox Tower and the Hollywood Theater.