The list of things beyond my comprehension is not a short one. At the top aren't mysteries of the ages such as "Why are we here?" or "Will humanity ever achieve world peace?" but rather — for the past few months, anyway — "How the hell did Paolo Sorrentino's latest not dominate awards season?" Spotlight and The Big Short are timely films. Youth is timeless.

The Italian writer-director's second English-language work is easily on a par with his 2013 masterpiece The Great Beauty. That picture earned the Foreign Language Film Oscar, so it's particularly baffling that this sumptuous follow-up was overlooked and underestimated.

Fortunately, Youth has finally found its way to a theater near you, offering the opportunity to experience the past year's best-kept cinematic secret. Even if the theater is not so near, I urge you to seek it out. Seeing this on anything less than a big screen would be sacrilege.

That's because Sorrentino, working again with the great cinematographer Luca Bigazzi, serves up dazzling visuals for a solid two hours. His setting is the Berghotel Schatzalp, the elegant Swiss spa that inspired Thomas Mann's The Magic Mountain. With its snow-capped peaks, manicured grounds and endless rolling fields, it's not a sight you want to squint at on a laptop, and there isn't a wide-screen TV wide enough to do it justice.

For years, two friends have made an annual pilgrimage to this exclusive place. Michael Caine gives the performance of his career as Fred Ballinger, a famed English conductor-composer. Harvey Keitel, likewise at the top of his game, plays Ballinger's friend of six decades, a Hollywood filmmaker named Mick Boyle.

The eightysomething musician considers himself "done with work and with life." The director, by contrast, is consumed with finishing the screenplay for a film he intends to serve as his "testament." All he needs is to write a final scene and to persuade Brenda Morel (Jane Fonda), the star of his early movies, to play the lead, thereby assuring financing.

Sorrentino's script is a masterful mix of the melancholy and the amusing. Fred and Mick stroll the countryside comparing notes on the number of drops they've managed to pee in a given day and recalling with undiminished ardor a woman after whom they both lusted half a century earlier. Rest assured, though: Their strolls never take them within a thousand miles of The Bucket List schmaltz.

These two observe and interact with the most intriguing menagerie of guests this side of The Grand Budapest Hotel. Paul Dano is superb as a movie star preparing his next part, who surprises Fred by quoting the German Romantic author Novalis. Miss Universe (Madalina Ghenea) impresses with her beautiful mind as well as her swimsuit-optional philosophy. Fred and Mick bet on whether a silent husband and wife will finally speak to each other over dinner. An obese soccer legend with a tattoo of Karl Marx covering his back drags his oxygen tank like a shiny dog on a leash. The spirit of Fellini walks among them.

If Youth's sights are inspired and indelible, its sounds are every bit as heavenly. In a climactic sequence, for example, we hear some of the music that made Fred a legend. It's beyond gorgeous. The piece is entitled "Simple Song #3" and was written for the film by Pulitzer-winning composer David Lang. The hairs on your neck will stand up.

And I've only scratched the surface. The movie is a marvel on more levels than space permits listing. It's a feast for the intellect, the senses and the heart — truly a great beauty. The year's greatest. It's just that simple.