I honestly don’t know what happened in Paul Thomas Anderson’s “Inherent Vice,” and I don’t really care. The first Thomas Pynchon book to be adapted to film, it was still utterly captivating, hilarious and endlessly fascinating. Like, literally endless. It was two and a half hours long, but I enjoyed every weird, nonsensical minute of it.

With multiple meandering plots, “Inherent Vice” is a stoned mediation on unsolved mysteries at the personal and global levels, and best enjoyed as a free-floating spectacle of cartoonish yet believable performances. Sit back and enjoy the ride through Southern California in 1970, abstractly picking up the vibes of films like “Chinatown,” “The Big Sleep” and even “The Big Lebowski.”

Katherine Waterson as Shasta Fay and Joaquin Phoenix as Doc in ”Inherent Vice.”

Katherine Waterson as Shasta Fay and Joaquin Phoenix as Doc in ”Inherent Vice.”

After all, Joaquin Phoenix plays a brother shamus, Doc Sportello, smoking weed and trying to solve various disappearances. (He even has a wandering daughter job.) His main concern is locating his ex-girlfriend Shasta and her current, married boyfriend, a real estate mogul into hard drugs and neo-Nazi biker gangs. He’s both hindered and helped by a lawman who is his polar opposite, Josh Brolin, aka “Bigfoot.”

Assisted by his attorney, played by Benicio Del Toro, and his part-time squeeze, an assistant D.A. played by Reese Witherspoon, Sportello also discovers something called the Golden Fang, which is either a drug cartel or a tax shelter for a bunch of dentists. One of the dentists is a velvet-clad drug fiend played by Martin Short, with a drawer full of cocaine and an office full of heroin addicts.

Doc also goes in search of a musician named Coy Harlingen, supposedly dead of a drug overdose but actually a snitch undercover, and then some. He turns up everywhere, and he’s played by Owen Wilson and we now know where the character Wilson always plays actually belongs. Everyone in this film is outlandish yet convincing, and he is one of the best.

The real key to this film is that you just want to watch Phoenix’s Doc character do any and everything. You want to follow him around because he’s so quietly personable and amusing, witty even when he seems hapless and well-connected despite his oft-remarked-upon hippie status. He’s utterly stoned and seemingly out of it, yet demonstrably competent in his varied exploits as a private investigator.

Director Anderson conjures a rich and complex time period using not so much period details, although there are those, too, as much as a powerful period vibe. He’s clearly a visionary film director; each of his films is so different, yet they share a total conviction to their world. “There Will be Blood” was epic, almost Biblical in its mythic tone. Washed in blood and black oil, it also dealt in black and white good and evil, while “Inherent Vice” is foggy, sprawling and shaggy, yet epic in its own way.

I’ll be the first to admit, I hated his film “The Master,” which also starred Phoenix, not to mention the late great Phillip Seymour Hoffman, but it is undeniable that the man has something to say. He has a signature, not to the more obviously stylistic extant of the Coen brothers or Wes Anderson, but in his case the signature is depth. Even in a world as shallow as that of Doc Sportello, where people die by falling off a trampoline and massage parlor brothels hang ludicrous “menus” on the wall, it is a world so deeply imagined that to watch it is to live in it.