On a recent weeknight at New York City’s Museum of Modern Art, the celebrated German designer Dieter Rams ambled up to a podium in his uniform of a black shirt, thinning silver bowl cut, and cane. He was there to introduce a movie, of which he is begrudgingly but indisputably the star.

“The film has my name, but it’s less about me, and more about my chief concerns,” the 86-year-old said with characteristic self-effacing charm.

Rams, who is famous for his clean-lined designs for home goods companies like Braun and Vitsoe, has many concerns—the state of the world, the state of design, the way our appetite for shiny, new things is leading us down a gluttonous path of destruction—and he voices all of them in the new documentary Rams.

The film is the newest from Gary Hustwit, who serves as the design world’s de-facto documentarian having made the lauded Urbanized, Objectified, and Helvetica. Unlike Hustwit’s other films, which center around concepts, theories, and ideas, Rams is very much a portrait of a person, despite its subject’s protestations.

Filmed over the course of nearly three years, the film follows the notoriously guarded Rams more than two decades after his tenure as Braun’s head of design ended. We observe him, aging but energized, padding around his austere home, which is filled with many objects of his own creation. We see him sweetly interact with his wife, who refused to be interviewed for the film to maintain her privacy. We watch him dance—sunglasses on!—with abandon (or as much as he’s capable of) to jazz in his home office.

The documentary is intimate and personal. It reveals a playful side of the designer that most people never see, and that many assume doesn’t exist given his famously sober aesthetic. But Rams goes beyond mere character study; it’s also a film with an agenda. “I framed it for him as a way to get his ideas about sustainability and consumerism and design out there for the next generation,” Hustwit says about the process of getting Rams to agree to the documentary. “I think that’s Dieter’s biggest regret, or what he’s most frustrated by—that he hasn’t been able to do enough to get that message out.”

Rams’ message is probably best summarized by his now famous catchphrase: “Less, but better.” Rams has always designed with an eye towards minimalism, but in the 1970s he began to explicitly rail against “thoughtless consumerism”— an idea that in retrospect looks healthy compared to today’s landscape of one-click orders and Dash buttons. There’s a tension to that sentiment, of course. Rams’ job was ostensibly to design products that would sell and make the companies money, but he aimed to design them in such a way that allow more space for “real life,” as he describes it. In Rams view, buying something should always be a choice, not a compulsion.