Thanks for no memoriesIn "Eternal Sunshine of the Spotless Mind," Jim Carrey is a man who wants to purge all memory of a love affair.

I just googled "lacuna" - the name screenwriter Charlie Kaufman gives to the experimental medical outfit that's central to his brilliant Eternal Sunshine of the Spotless Mind. The first link I clicked on: www.lacunainc.com, which boasts a nice photo of Dr. Howard Mierzwiak (Tom Wilkinson), the character in this fractured fairy tale who's invented a process by which painful recollections can be erased from the brain. (Yup, it's one of those bogus studio-sponsored Web sites that riffs on the illusion(s) offered in the film, and serves as a clever marketing tool to boot.)

Scroll down a little further on Google, past the links for an Italian goth-metal band called Lacuna Coil, and you'll eventually get a definition: lacuna, a word used in bookbinding for an area of a manuscript "that is completely missing as a result of . . . damage. The word derives from the Latin expression for gap."

Ah, the many splendors of the World Wide Web.

The gap, the stuff gone missing, the ripped pages in Eternal Sunshine, is memory. Joel Barish (Jim Carrey), a Long Island sad sack who keeps a journal full of low-self-esteem haikus, has opted to erase the whole, roiling, up-and-down affair he has had with a kooky beauty by the name of Clementine Kruczynski (Kate Winslet). Like 50 First Dates, Paycheck, Memento, and The Man Without a Past, memory - or the lack of it - is key. And like the portal that transports people inside other people's heads in Kaufman's Being John Malkovich, Lacuna Inc.'s mind-clearing process is the sci-fi hook on which Kaufman and director Michel Gondry have hung their hats.

And hung their hearts.

Because, at its core, Eternal Sunshine is anything but science fiction: It's a trippy but tender examination of human emotions, relationships, all-consuming love.

With a performance from Carrey that is as inspired as it is uncharacteristically subtle and subdued, and a revelatory turn from Winslet as a heartbreaking Barnes & Noble clerk and "free spirit" (she dyes her hair Day-Glo hues, she says what she's thinking, she likes to get ripped), Eternal Sunshine is a labyrinthine love story. It's funny, sad, fraught with suspense and freak-out episodes. The narrative circles back on itself, flashes forward, loops around, and does triple somersaults - and still makes whip-smart sense. It quotes Alexander Pope and Nietzsche.

I'm not sure how Kaufman and Gondry have pulled it off, but the internal logic of Eternal Sunshine works like a dream - literally.

So too does the supporting cast: Wilkinson's lab-coated brainiac is stoic and eccentric, harboring a secret of his own; Kirsten Dunst is utterly charming as the doctor's wifty office assistant, idolizing her boss from afar and sharing tokes and beer with a pair of Lacuna lab techies played by Mark Ruffalo and Elijah Wood. (Wood's blithely creepy Patrick is as geekily of this 21st-century moment as his pop-eyed Frodo was of the far-ago Middle-earth.)

Visually, Gondry flexes his music-vid muscles - but never gratuitously. Jon Brion supplies an eloquent, pop-inspired score.

There's a mystery element to Eternal Sunshine - not a whodunit, but a whendunit - and a where-are-we-now and what-just-happened dunit, too.

I could google "sublime," but I already know what the word means: It means Eternal Sunshine of the Spotless Mind.

Contact movie critic Steven Rea

at 215-854-5629 or srea@phillynews.com.

Eternal Sunshine of the Spotless Mind

**** (out of four stars)

Produced by Steve Golin and Anthony Bregman, directed by Michel Gondry, written by Charlie Kaufman, photography by Ellen Kuras, music by Jon Brion, distributed by Focus Features.

Running time: 1 hour, 48 mins.

Joel Barish. . . Jim Carrey

Clementine Kruczynski. . . Kate Winslet

Howard Mierzwiak. . . Tom Wilkinson

Mary. . . Kirsten Dunst

Patrick . . . Elijah Wood

Stan. . . Mark Ruffalo

Parent's guide: R (profanity, sex, drugs)

Playing at: area theaters