Joaquin Phoenix in Paul Thomas Anderson’s “Inherent Vice.” Courtesy of Warner Bros.

I frankly didn’t know what to make of Paul Thomas Anderson’s “Inherent Vice” the first time I saw it. I hadn’t read the Thomas Pynchon novel upon which it was based, and the plot was so convoluted that it left me feeling more bewildered than intrigued. I couldn’t follow it, but more importantly, I didn’t care about it either. If a mystery doesn’t immediately hook you, as it did so effectively in David Fincher’s “Gone Girl,” then it becomes a chore to follow. Thankfully, the film is less concerned with the plot itself than with the bystander at the center of it, stoner private eye Doc Sportello, played by Joaquin Phoenix in a performance that proves he’s not only one of the best actors working today, but a tremendously gifted physical comedian.

Doc often misinterprets what he hears, even the simplest of asides. While on a phone call, the guy on the other line tells his son to go to bed, causing Doc to indignantly ask, “Why would I go to bed?” He’s also hopelessly inept when it comes to jotting down information. After being informed of a key spanish term and its meaning, Doc scribbles down, “Something Spanish,” on his notepad. Thus, it’s a wonder that Doc is able to somehow navigate his way through the labyrinthine plot set during the L.A. twilight of the psychedelic 60s, with his ex-girlfriend Shasta (Katherine Waterston) materializing every so often like a drug-fueled apparition. A colleague of mine pointed out that the voice (Joanna Newsom) narrating the film may very well reside in Doc’s head, since it’s simply articulating his thoughts in the third person and is embodied by an alleged friend (perhaps a memory of one) that ONLY Doc acknowledges. Everyone remains oblivious to her presence and there are even a few scenes where she appears in the front passenger seat of Doc’s car only to vanish in the next shot. Continuity error? Time jump? I vote neither.

When I saw “Inherent Vice” a second time at its premiere public screening in Chicago, it was toward the end of a very busy week plagued by miserable arctic temperatures. Turned out a second helping of the film accompanied by a theater full of PTA-loving chuckleheads was precisely what the Doc had ordered. Suddenly the plot was no longer a nuisance to me. It didn’t matter that I couldn’t nail down all the details, the overarching themes still resonated. Some sections of the film border on monotonous, but the majority of it is laugh-out-loud hilarious—that is, as long as you get on its groovy wavelength. Coming out of the theater, a woman behind me asked her companion, “Was everyone in the theater high? I haven’t heard so much giggling in my life.”

A lot of things in the film made me giggle—and they proved to be even funnier on second glance. The real love story in the picture takes place between Doc and a man who would appear to be his opposite in every conceivable way: a pancake-loving meathead cop and frequent “Dragnet” extra nicknamed “Bigfoot” and played by Josh Brolin in what is surely one of the most entertaining supporting performances of 2014. Brolin has displayed comedic flair in various roles prior to this one, such as his bisexual cop who flirts with Patricia Arquette in David O. Russell’s great “Flirting with Disaster,” but his role as Bigfoot could give him “Lebowski”-level immortality. Watching him attempt to savor and eventually choke on a chocolate-covered banana, as Doc looks on with fascination and disgust, is a showstopper, as is the tense meeting between the two men in a restaurant where Bigfoot shouts the soon-to-be-legendary line “Moto pancaku!” The scene ends with him repeating the line in close-up for no apparent reason, aside from earning an easy laugh.

It’s during moments like these that the film emerges as PTA’s first pure lark, lacking the dramatic heft of his previous pictures, save for one jarring sexual encounter between Doc and Shasta, performed fearlessly by Waterston, that momentarily brings the laughs to a squirm-inducing halt. It’s the most off-putting scene in an otherwise richly enjoyable film. It’s wonderful to see veteran comic geniuses like Martin Short and Jeannie Berlin pop up in inspired cameos. A shame that more screen time wasn’t given to a perfectly cast Timothy Simons, best known as the uproariously self-important errand boy Jonah on HBO’s “Veep,” as an equally clueless FBI agent resembling the human equivalent of Sam the Eagle. While interrogating Doc, he picks his nose, thus inexplicably triggering a chain reaction of nose-picking amongst his fellow agents in the room. You laugh, if only at the weirdness of it all.

“Inherent Vice” has received wildly mixed reviews from critics and a lot of head-scratching from the general public. Years down the line, it will be regarded as either a neglected masterpiece or a strange anomaly in one of the great modern filmmaking careers. As for me, seeing it last night, it worked perfectly well as a stoner noir. It currently stands as my least favorite Paul Thomas Anderson film, which isn’t saying much, considering that I love all of them (yes, even “Hard Eight”). “There Will Be Blood” wasn’t anywhere on my Top Ten List of 2007, and now I believe it’s the best film of that year by far. “The Master” has gotten better every time I’ve seen it, and the same thing happened with “Punch-Drunk Love.” With “Boogie Nights” and “Magnolia,” it was love at first sight. It’ll be interesting to see what I think of “Inherent Vice” a year from now. It didn’t quite crack my Top 20 list, but it gave me quite a high indeed.

“Inherent Vice” opened Friday, January 9th, in Chicago.