Mike Mills has something of a fixation with the recent past. When I call him on his cell phone a few days before the January 20 wide release of his latest film, 20th Century Women, he explains to me that he's just discarded his iPhone in favor of a flip phone. “I was trying to get off the digital habit, just to get the fuck off the iPhone drug chain,” he says, laughing, “but this new phone just has a world of problems. Every time someone texts me, it dings forever. Do you remember having to click the numbers to switch letters? I'm not sure this is gonna work.”

That desire to travel back in time extends to Mills's films, too. 2010's Beginners followed Christopher Plummer as Mills's father, a closeted gay man who embraced his sexuality late in life. 20th Century Women is inspired by Mills's freewheeling, 1970s-California childhood, which was rife with intense, fascinating women. Jamie (Lucas Jade Zumann) is Mills's avatar, a disenchanted 15-year-old who, appropriately, spends much of the film basking in the glow of said women: Greta Gerwig plays Abbie, a punk artist based on Mills's sister; Elle Fanning plays Julie, a thoughtful and tortured amalgamation of Mills's own teenage friends; and Annette Bening is Dorothea, Mills's singularly brilliant and strange mother. Well, sort of. “There are really three people going on there, maybe four,” says Mills of Bening's character. “There's my real mom, who's sort of a mystery and who's been gone for a long time. There's my version of her I wrote in the script, a version that's not pure or innocent, not exactly her — my mom would write a different version, my sisters would write a different version. There's Annette Bening, who's the right age and also a Gemini, which I find massively interesting. And then there's Dorothea, the creature that Annette created. They have some connections, and they all see each other, but the end result is even confusing to me.”

That end result is also one of 2016's most sensitive, moving portraits of women's private and public lives, a particularly insightful look at the way we relate to and try to understand ourselves, each other, men, our families, our bodies, music, books, love, loss, growing older, etc. I asked Mills about everything from his feminist underpinnings, to the process of casting his own family members, to emailing with Judy Blume, to his “New Age-y” conversations with his mother's ghost.

MTV News: As a woman, I felt very understood and “seen” by this movie in a way that I don’t often feel when watching movies written and directed by men. Most of the women I know who’ve seen this movie have voiced something similar, which is a little depressing, on the whole. Why do you think you, in particular, were capable of directing a movie about women with such empathy and depth?

Mike Mills: That's a nice compliment. I grew up with a very strong mom and two very strong older sisters, and a gay dad who was in the closet. So I was the only straight man in my house, and I was the little brother by 10 years. It was a very matriarchal home, and the women held all the power. The women were the most interesting thing in the house, and everything was focused around them. They really were my allies and my friends. My dad was very sweet, he just didn't try, in a way. And so my whole life, I've been listening to women, ruled by women [laughs].

I'm not perfect; I think my wife would say I'm a good feminist four or five days out of the week. And being a dad, it's really crazy how gendered things are, biologically and otherwise. We live in a patriarchy, a world that's dominated by men making things, and that's been normalized for so long, for all of history. We normalize [men's] shortcomings too much. Even as a guy, as a Pisces, a sensitive straight guy [laughs], I get mansplained to, too. It's not the most enjoyable intellectual or emotional space for me either. But again, I'm not innocent. I remember I talked too much in grad school and in college, because that was something that had been given to me by the culture. Luckily I have a feminist wife who will call me out frequently about assumptions I'm making, or privileges I'm unconscious to, or biases I'm unconscious to.

You do address that in a certain sense in the movie — the character of Jamie is sort of a vessel for these women to understand themselves better, even a vessel for feminist theory itself.

Mills: Imagine the power dynamics of being a little brother by 10 years to women in their teens and early 20s in the '70s and early '80s, women who had wild lives. I am the recipient of not even an intellectual feminism or a theory-based second-wave feminism, but just of their actual lives. Hearing about their sex lives, getting into trouble, messing with my parents — I'm the witness of that. The feminism that I know comes very much from growing up with these women, and then I was exposed to a real feminism in college. The women's studies classes I took in grad school were really important to me growing up in my strange house, where my mom was sort of the “man” of the family and literally quite butch, and made the money, was a pilot and a draftsperson. And my dad was a closeted gay man. So the dynamics were very strange.

When I was writing the film, I was trying to find ways to show my limitations. I was really happy when I got Elle's character, Julie, to say, “That's your version of me. That's not really me.” That was a key line in the film, to me.

Outside of your mother, who I know has passed, what’s been the reaction to the movie from the women you based it on?

Mills: Greta's character is based on my sister to a degree, in that my sister went to New York, found a more exciting form of feminine sexuality, went to art school, discovered she had cervical cancer, had to come home, and thought she couldn't have kids. [So] the biggest one is my sister, since she really gave me a big hunk of her life. I interviewed her, we talked about it. She was very generous. She had this phrase, like, “Maybe this is adding to the sort of compost version of humans, what it means to be human.” She's very giving in that way. I think she really liked the movie. And she and Greta had their own conversations. That was really important to me — being a male guy, writing this script, it was important to have these two women talk to each other without me there. And they ended up having a really interesting conversation about sexuality and empowerment that my older sister just naturally wouldn't have with me.

The women Elle is based on I haven't known for decades. I don't know if they see themselves in the film. But I did interview some women who are friends of mine now to get some facts. So, like, Abbie's first period that she talks about in the dinner party scene, and Julie losing her virginity — those are quotes from two of my friends' real lives. And other things, too: The book Julie reads, her smoking, where she hung out, even her double life.

When she’s shown reading Forever, that struck me as particularly real — every woman I know read that book around that age.

Mills: It was funny, we had to interact with Judy Blume to get permission, and I ended up emailing with her. She was so generous with us, but she reminded me about how attacked that book is for its sexuality. I just remember all my female friends at the time reading it, being like, “Woo hoo! This amazing, hot book!” But [Blume] was really trying to do something very authentic and real, and she got reduced and pigeonholed as [having written] this sexually scandalous book. She was very particular about the quotes that we could use, coming from this attacked place.

Each cast member seems so comfortable in their character’s skin. Annette is particularly perfect. How’d you cast your own mother?

Mills: That's a tricky one. You've been through a lot of versions [of her] in your head; it's messy, it's not some stroke of epiphany or genius, like, “I got it!” And of course, Annette on paper seemed perfect. She's the right age, and she looks beautifully her age, beautifully real. And that was really key to me, especially for this woman who has an Amelia Earhart vibe. Annette was really sweet — we had to dye her hair gray, and she had to be in a chair for hours at a time, and she got that I really wanted this amazing, iconoclastic, strong, middle-aged, gray-haired woman. Which was very much my mom. And Annette liked the script, so I was very lucky. She has such depth of experience as a mother, a woman, such emotional intelligence and curiosity about people who aren't neat and trope-ridden. She's down with that, their contradictions and ambiguities. She's excited by that. So we had dinner, and it was like, “Game on.”

I don't know why the others are so perfect, but I agree, they really are. Greta really does feel like a punk chick from the '70s, and I can believe her as a photographer, as an artist. It was really fun to have her play a more dramatic role. She really inhabited that sadness and trauma in such a real way that honored that situation so beautifully.

Elle is really interesting. When you think of a 16-year-old, 17-year-old, Elle Fanning is at the top of any list, in terms of experience. But when I met her, I realized, she really is like these girls I'm talking about, in that she's so pretty and blonde and sweet-looking. It would be easy to write her off as kind of a pretty, benign sex object, but once you start talking with her and acting with her, she has access to real dark things, strength, contradiction.

It's much like these women I'm talking about, who I didn't know in a boyfriend way, who'd crawl through my window after having sex with other guys and tell me everything, and not just the fun or wild stuff, but their real concerns.

As a writer, I’m curious how you talk yourself out of that voice that tells you your own specific experience — or writing from the first person — isn’t significant, or isn’t universal, or won’t translate.

Mills: Oh, I've suffered. You just hit my Achilles heel. I beat myself up a lot about that. I still worry about that, even though the film seems to be connecting very interestingly with people. I'm not that confident or proud or iconoclastic of a person. But I do love Allen Ginsberg, Lydia Davis, Fellini, Woody Allen in the '70s, all these people who use their personal lives. Even [those who use] simply everyday life, like Mike Lee or the Argentinian director Lucrecia Martel: eating, sleeping, sex, relationships, jobs. That can feel really indulgent, too, even though it's normal and something we should all relate to. I just believe that concrete details have so much life embedded in them. You don't have to relate to the life exactly; in my last film, I had so many details about my dad that were unexplained or unpackaged, and people could connect to them even if they weren't elderly, recently-out gay men. But whenever I walk into a screening of my movie and I see a bunch of strangers, one of the first things that happens to me is that in my head I go, I'm sorry. I'm sorry I TMI'ed over all of you. I didn't mean to.

Your first movie, Thumbsuckers, is about a kid sort of learning to unyoke from his parents. What is it that compels you to make movies about parent-child relationships, and has your understanding of it changed now that you're a dad?

Mills: I didn't know I'd be making three movies about that, and they for sure are. I guess consciously — but largely unconsciously — I think that's the most important terrain, that's how we form ourselves. All films are kind of about child and parent relationships. I guess [it's a way] to train the process of therapy and analysis on me, that process of trying to understand yourself by going through your own personal history, trying to extract the narrative you've learned about yourself, trying to get yourself out of the prisons you've made. That is very much a family project [laughs]. I had my son a year into writing the script, and it did, in ways that are hard to explain, kind of tie me closer to my mom. When Annette is talking about parenting in the film — “You get to see him out as a person and I never will,” “You love him so much you're kind of screwed” — that's me talking through my mom's mask.

How involved is Miranda [July, who is married to Mills] in your creative process, and vice versa? I ask because you’re both filmmakers, but also because you both make such vulnerable and personal art.

Mills: We met as grownups, already kind of having our work and our established way. We work really differently, you know? So we actually share very little. We talk about things that are bugging us, but we don't talk about, “Okay, I'm stuck at this part of the script and I don't know what happens next,” the nuts and bolts of the creative voice. Because that's kind of private and personal and not super shareable. Through the three years I wrote the script, Miranda read it once, and she was very critical and very helpful. She saw the movie once in my editing process and had some really great insights that really helped me. I was really doubting the film when I showed it to her, and that she liked it at all was a huge boost for me. That's really important. Even if we're disagreeing on things, because she's such a known landmark to me, I know how to triangulate off her reading of me. It's like geolocation. It's a trip, actually.

This movie has so many amazing dancing scenes. How did you direct those? How’d you pick the music? Was any of it choreographed?

Mills: Annette and Billy [Crudup] dancing to Talking Heads was in the script, and we figured it out on set, and I remember my main thing I had to tell Annette was, “Stop using your hips so much. This woman doesn't know about her groin.” We had two weeks of rehearsals, with lots of improvising and experiential stuff. We'd have dance parties, with different music for each character: Elle was into Fleetwood Mac, Billy was very '70s, Abbie and Jamie were very punk, Annette was Glenn Miller. It sounds like Acting 101 stuff, but it was really informative for the characters to meet the energy and culture of the other characters in that non-intellectual way. That's all in the script, but the way that Greta dances, that's her creation. I don't think that's how Greta Gerwig dances herself, but I think that dancing is historically correct. When she teaches the boy how to dance — that came out of a rehearsal. When they first met, I asked her to pick a song and teach him abandon, freedom. She went over and pulled and tugged at him like she does in the movie, and it was really beautiful to me. It was part John Hughes, part something more emotional.

When they all danced to Glenn Miller at the end of rehearsal, they did that thing of dancing and switching partners and dancing arm-in-arm. Just watching it, it was a physical realization of what I was hoping to say in the film about transient relationships, connections that come and go and are very sweet but not permanent. So I put that in the hotel scene at the end — it was originally just them all watching TV together.

We learn that Annette’s character dies early on, but the real gut punch at the end is when we also learn that she and her son never really connect in that real way again, that Julie and Jamie lose touch emotionally. Why did you decide to end it that way — was it because it was what happened in real life?

Mills: Basically. I had that sentiment early on in the writing process, I was like, Oh, I just really like this, it feels really true to me. Even these deep, incredible relationships — me and my mom were so intertwined, but in other ways, we were so blind to each other and unable to be together. And that never got resolved, really. That was there till the day she died; there was this gap.

How do you think your mom would react to you having made a film about her?

Mills: That's the million-dollar question. She's been gone for a while now. I think that in some ways she's a very private person, and I'm sure she would disagree with the way she was characterized or reduced. She's a Gemini, and Geminis don't like being pinned down, so they certainly wouldn't want a film being made about them [laughs]. Things have changed so much since she died. I had to tell her ghost, “I'm trying to make this movie. I'm not sure how you're going to feel about it. I feel fairly confident that I'm making it with a lot of love and attempts to understand what it was like to be you. But I understand you're probably not down with it.” That sounds New Age-y, but I had to go through all that to even start. I had to go through it again and again and again, actually.