“The Diary of a Teenage Girl,” based on the graphic novel by Phoebe Gloeckner, follows 15-year-old Minnie Goetze (Bel Powley, in a star-making performance) as she goes on a journey for love and acceptance, and as the movie begins she has already started to experience her sexual awakening. She becomes embroiled in an affair with Monroe Rutherford (Alexander Skarsgard) who also happens to be her mother’s (Kristen Wiig) boyfriend. What results is an honest version of what it’s like to be a teenage girl, and the movie isn’t so much about sex as it is about finding your own self-worth which is very important for young people making their way through this crazy world we all inhabit.

This movie marks the directorial debut of actress and writer Marielle Heller, and I got to talk with her and Bel Powley while they were at The London Hotel in West Hollywood, California. One of the things I remarked about it was how beautiful the movie looked and of how it really transported the audience back to the 70’s. Granted, “The Diary of a Teenage Girl” does take place in San Francisco, California which, after all these years, hasn’t changed much since the 70’s, but director of photography Brandon Trost still did terrific work in bringing us back to a time period which is gone but not forgotten.

Marielle Heller: I love telling people that the same person who shot this movie also shot movies like “The Interview” and “Neighbors” because they couldn’t be more different in terms of content. But he is a real artist and I think he just did the most incredible job. He was so dedicated to making this film look and feel exactly how we envisioned it which was in some ways like an old Polaroid picture, but not with a hipster grossness on it. We wanted it to be really authentic to the story and to the characters.

Those who know Heller best know that she has been in love with Gloeckner’s graphic novel ever since her sister gave her a copy of it 8 years ago. She spent a long time trying to get the rights to adapt the book into a stage play, and she performed the role of Minnie Goetze herself in an acclaimed off-Broadway production. From there, Heller went on to develop “The Diary of a Teenage Girl” into a screenplay at the Sundance Labs, and the film eventually debuted at the 2015 Sundance Film Festival.

Having spent so many years with Gloeckner’s graphic novel, I asked Heller how her view of it has evolved from when she first read the book to when she began turning it into a movie.

Marielle Heller: The film version of the book had to take on its own new life and really shift and change because the narrative structure of a film has to have a different build than a novel can. You read a book and you put it down and you pick it up and you put it down and it can have a really episodic feel, and a movie has to have a really specific kind of emotional build. I had such reverence for Phoebe’s book. I loved it more than anything I had ever read before, which is sort of a problematic place to start an adaption from. It was too much love, too much reverence, and at some point I had to sort of give myself permission to destroy parts of what I loved too and let go of it and let the reverence go away. Things changed, storylines changed, so that was a big process and luckily Phoebe really understood that because she’s such an artist herself.

Heller also remarked about a conversation she had with Gloeckner during the making of the film:

Marielle Heller: She was like, “You have to do what you have to do for this process. I took my real diaries and I wanted to make them into a piece of art. I didn’t want to write a memoir. I wanted to change them and let them become something new and let them become a book, and so I put them through this big grinder and it came out the other side hopefully with some truth intact. But it was something new, and then you took it and you put it through another kind of meat grinder and out the other end came this other project and it’s something new and hopefully that kernel of truth is still the same.” So it’s been a long process and in some ways I internalized the whole book. I got to know it inside and out and then stopped looking at it and wouldn’t let myself look at it and let the movie just grow into something totally new.

Watching “The Diary of a Teenage Girl” reminded me of my favorite movies which dealt with adolescence and being a teenager like “Pump up the Volume,” “The Breakfast Club” and “Ferris Bueller’s Day Off.” I love movies which take adolescence seriously as so many others treat it like life won’t get any better than when you’re young. I asked Heller and Powley what their favorite teen movies which they felt treated being a teenager honestly were, and their answer pointed out how those movies are missing a particular point of view.

Marielle Heller: I think there are a lot of movies that deal with adolescence in an honest way for boys. I hadn’t really come across ones that really dealt with girls in an honest way which is why I think we wanted to make this movie. I know I really related to movies like “Stand by Me” or “Harold and Maude;” movies that felt like they were, like you said, really respecting the characters and giving adolescents a voice in it. And John Hughes’ movies too like “The Breakfast Club” and “Sixteen Candles.” Movies like that really did give voice to the teenager in a real way. And I guess actually that John Hughes did make movies about girls. “Sixteen Candles” was about being a girl, but we’re a long time from “Sixteen Candles.” We’re due for another one.

Bel Powley: I was a teenager six years ago (laughs), and I don’t think I related to anything. I found it really hard, and I think it honestly made me feel like really isolated and really alone. I think young female characters are presented in such flat, two dimensional ways especially when it came to sex. Like if you did have sex then you were this high school slut, or if you didn’t then you’re either frigid or you’re like this virgin waiting for your Prince Charming. I remember being so excited when “Juno” was coming out, and then it came out and it was like, well no one speaks like that. And also, she’s made to be kind of asexual. It was just so confusing to me, and I honestly didn’t relate to anything until “Girls” (the HBO series), and that was when I was like 19.

Hearing Heller and Powley say that makes you realize how important “The Diary of a Teenage Girl” is in today’s cinematic landscape. For once we have a movie that deals with the life of a teenage girl honestly, and that makes it all the more important for audiences to seek it out in the midst of another overcrowded summer movie season. It is truly one of the best adolescent movies made in recent memory, and it deserves your attention far more than many others in this genre.

“The Diary of a Teenage Girl” is now available to own and rent on DVD, Blu-ray, and Digital.