There’s a moment in Noah Isenberg’s terrific We’ll Always Have Casablanca where the author speaks directly to the film’s enduring legacy. Casablanca, after all, is one of Hollywood’s most cherished and celebrated films; as Umberto Eco once perfectly said, “Casablanca is not one movie, it is movies.” What draws people back time and time, in part, the book posits, is nostalgia. But not the kind of nostalgia you’d expect, Isenberg writes. It’s not a longing for what was that brings us back to Casablanca’s nobility, heroism, love, and sacrifice—it’s a longing for what could have been.

Peter Bogdanovich, I think it’s safe to say, had a heart filled with both kinds of nostalgia. And each part, in equal measure, made him one of the greatest filmmakers, and film scholars, that ever lived.

In so many ways, Peter’s work can be defined by the past. He began his film career interviewing the greats—Hawks and Ford, Hitchcock and Welles—obtaining profound insights into their work, which he absorbed and later used as the foundation of his own artistry. If you read his interviews, you not only get a sense of how sharp Peter’s mind for film was (even in his 20s) but how exuberant he was about these aging masters. Bear in mind, Peter was conducting these interviews in the last 1960s, a time well before the proliferation of resources that make film as accessible as it is now; the knowledge Peter had, and his commitment to film’s history, required true zeal—and that zeal endured throughout Peter’s entire life.

Watching Peter’s work, you can see his love of the golden age of Hollywood. What’s Up, Doc is a loving tribute to the screwball comedies of the 1930s and ‘40s, like Bringing Up Baby and It Happened One Night; similarly, At Long Last Love is a homage to musicals of that same era—Peter went even so far as to record the music and singing live and not dub it later, something that no film had in forty years. I heard him talk about how arduous filming that movie was because of that decision, but he has determined to capture the authenticity of that period. Peter was a trailblazer and a rule-breaker. You can’t limit his body of work to a single genre, and you can’t even define his career with a single word. He was a director, an actor, a raconteur, and a scholar. He did it all, and he did it in his own indelible way.

You can’t watch Peter’s finest film The Last Picture Show—which I’d argue is one of the best movies ever made—without recognizing the steady camerawork of Howard Hawks and the occasional flourishes of Orson Welles. The same can be said of Paper Moon. But Peter’s work was much, much more than loving tributes to the greats. He had a style all his own, great empathy toward his characters, and a clear, obvious desire to cast the spell over audiences that only cinema can conjure, once that transports us all into a whole new world. As Martin Scorsese said, Peter’s films seemed look forward and backward at the same time, and there’s more magic in that alchemy than I could ever hope to put into words.

With Peter’s passing, we lose not only a wonderful human being and a gifted artist, but we lose a bridge to the past. I’m a passionate cinephile; I’m one of those people who not only loves Hollywood’s golden age, but I also believe an appreciation of film’s history is essential to film’s future. Nobody embodied these values better than Peter did. But, unfortunately, we’re living in a time where the word ‘nostalgia’ has become a mindless buzzword that not only has little to no meaning, but it’s exonerated people from engaging with the past. You’ll find people on social media—people who make movies, believe it or not—who are outright hostile to cinema’s history, who scorn movies made in black and white. They actively devalue the medium’s rich and magnificent history, and it feels, at times, like those voices are growing louder and louder every single day.

Meanwhile, voices like Peter’s are fading away or leaving us altogether. Peter was a man who celebrated and preserved film history while moving the medium forward, and that should never be forgotten. He made groundbreaking films of unparalleled artistry while also ensuring cinema’s rich history survived for anyone who wanted to appreciate it and learn from it, just as he did. In the past few years alone, Peter salvaged Orson Welles’s lost film The Other Side of the Wind, and he directed The Great Buster, a documentary about the groundbreaking silent star, Buster Keaton. And this is just the tip of the iceberg. Peter was known for his generosity of time and spirit; he’d forgotten more about film than even most of us can ever hope to learn, but he seemed always willing—eager, even—to share all the anecdotes, all those stories he’d lived and accumulated, over a lifetime lived in film.

There’s a hole in cinema with Peter’s passing, there’s no doubt about that. But, fortunately, Peter left behind the books he’d written about his heroes and countless interviews; he recorded scores of DVD commentary tracks, and while I haven’t heard them all, the ones I have listened to are remarkable. He was also the subject of TCM’s inaugural podcast season, The Plot Thickens, and I urge people to give it a listen—it’s a tremendous look at Peter’s life and work.

Peter also leaves behind some of the best movies ever made. And baked within them is his passion for cinema, his knowledge of the past, and his genius that helped reinvent the entire medium. It’s all there, waiting for anyone to pick up, study and learn from, and do what Peter did—continue the legacy of film in ways both old and new.