When she was barely 22 years old, actress Allison Williams performed a mash-up of Nature Boy set to RJD2’s A Beautiful Mine, the theme song to the TV series Mad Men, which was then posted on YouTube. Professionally produced, it was no backyard enterprise, but it was recorded live with no editing, dubbing, lip-synching or auto-tuning.

The clip went instantly viral and became, inadvertently, an audition for the HBO television series Girls, Lena Dunham and Judd Apatow’s four-girls-in-New-York antithesis to its more anodyne predecessor, Sex and the City. Girls became more than a television series, it was a cultural revolution encapsulated in a moment in time.

“It’s been almost 15 years since we shot the pilot, and so that stage of my life is in my rearview mirror very comfortably,” Williams says now, as we sit down to discuss her new film, Regretting You. “I feel so lucky for how my life has unfolded, but I wouldn’t yearn to be back in my early 20s again.

“I feel like I really did them, [but] I did them twice,” Williams says. “I did them as myself and I did them as [my character] Marnie, and I feel like the way the show is being digested [in the here and now] is with so much more goodwill and benefit of the doubt and less acidity. What is so refreshing talking about it at this point is the distance from it.”

Regretting You is based on the 2019 novel of the same name by Colleen Hoover. Written by Susan McMartin and directed by Josh Boone, it stars Williams as Morgan Grant, a wife and mother whose life sits in a complicated nexus in the form of daughter Clara (Mckenna Grace).

The fractious mother-and-daughter relationship is held in a state of stable calm only because of the presence of husband and father Chris (Scott Eastwood), and that relationship begins to unravel when Chris dies, leaving Morgan to sift through the remains of their marriage and the secrets that it contains.

It might seem like a long bow to draw at first, but I suggest to Williams that there is an echo of Desperate Housewives in the air, not in a literal sense, but in a thematic sense. Marc Cherry’s hit television soap opera, which ran between 2004 and 2012, tapped into something compelling: that women often do live complex interior lives.

He took a conversation with his mother, in which she suggested that many women “lead lives of quiet desperation” and turned it into his show title, but the deeper themes are richer, the suggestion that even in relationships where honesty is exchanged, there are a myriad more personal layers that are often held in check.

“What I imagined being the most excruciating thing would be to be aware of something consciously and hold it privately,” Williams says. “That feels like it would be agonising. There are other characters in this story who are living that existence, Morgan is not.

“Morgan, at the beginning of the movie, and in the book, describes herself as feeling a hollowness,” she says. “She’s feeling an emptiness, and she can’t quite put her finger on what it is. And then of course all these things happen and so then that process is interrupted by all these other things she has to process emotionally.”

There is also a faint reminder of another work of Williams’, the critically acclaimed political thriller miniseries Fellow Travellers, based on the Thomas Mallon book, about a closeted high-ranking government official, Hawkins Fuller (Matt Bomer), who eventually marries a senator’s daughter, Lucy, played by Williams.

“She spent many years wondering, and the wondering is a place that I’m sure she felt nostalgic for once she knew and then had to decide, like, what are the rules of the road here? What do I want to do?” says Williams. “That feels much more like quiet desperation. Morgan’s [situation is different], she’s ignoring other things, but she is finding it harder and harder to just ignore and push down those feelings.”

The novel on which the film is based is immensely popular, and part of a fan-created literary (and now cinematic) universe referred to unofficially as “the Hooververse”. While they are not likely to come for writers, directors and actors interpreting Hoover’s work in the same way Star Wars and Star Trek fans react to departures from established canon, Williams acknowledges they’re in the room.

“From the producing team and Josh and certainly myself as an actor, [we are] very aware,” Williams says. “First, I consider myself part of that group. I’m not as vocal, but I do have strong feelings about the characters I read in books, period. I always have. It’s a very intimate relationship with you and this page and your imagination.

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[But] they’re sophisticated, they know that a book is longer than a feature film,” Williams adds. “They know that something has to go, they know that some elements of the story have to take priority over others. They understand how this process works. They’re just looking to see what kind of choices we made.”

In purely commercial terms, Williams’ career popped with Jordan Peele’s horror masterpiece Get Out (2017). Peele has said he deliberately cast Williams because he thought her established screen persona – the girl-next-door, essentially – would disorient the audience.

That step into the horror world led her to her most recent, and certainly most famous, screen performance: Gemma Forrester, the roboticist who creates the robot M3GAN in the 2022 film of the same name. A sequel, M3GAN 2.0, came out this year.

At the same time, Williams has created for herself a high-profile real life, hosting the podcast Landlines, with her two best friends, early childhood educator Hope Kremer and therapist Jaymie Oppenheim. The podcast tackles the loose themes of adulthood and parenting, but its conversations are replete with candid and illuminating exchanges.

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The podcast group also gave Williams a forum to tackle some of the themes of Regretting You – without giving away too many spoilers, let’s say they’re grief and betrayal – with people who might have some insight into them.

“We’ve all experienced loss in our lives, and being able to turn to each other for that support has been extraordinary,” she says. “And obviously, having a therapist in your friend group is very helpful when you’re grieving or when you’re trying to process any emotion, really.

“But that is the case anytime you have a group of friends that have been fellow passengers in life together for this many years, you’re going to have all those vicissitudes that come along with it, and we are no exception,” Williams says.

“It also means that they just understand the full range of things that I’ve gone through in my life, many of which I drew on to be able to do this performance,” Williams adds. “Sadly, none of us gets through life without experiencing grief and loss of some kind, and so if it weren’t for their support, making it through those moments would’ve been much, much harder.”

Time also brings a change of perspective, she says. When Girls came out, for example, “there was something about Lena, there was something about the privilege and the seeming lack of perspective of all the main characters and thus the show in and of itself, which is absurd,” Williams says. “The vitriol was so incredible while it was airing, so now it’s like people have [a] better perspective on it.”

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For a new audience, seeing it for the first time, “it’s resonant, it’s just whatever felt real enough about our dialogue and the dynamic between the characters, that felt so real that it made it hard for people to watch and enjoy [at the time], must still feel real and resonant and in a positive way.

“Whatever it is, I can’t claim to be able to diagnose it [but] I’m extremely grateful,” Williams adds. “It is the gift that keeps on giving and the show that I will enjoy talking about for the rest of time. It was a dream and I just keep hoping that we’ll get to make more some day, [that we will] be back together.”

Regretting You is released in cinemas on October 23.

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