Though the title of the movie is lifted from a poem by Alexander Pope, "Eternal Sunshine of the Spotless Mind" takes its main philosophical cue from another British wordsmith, Lord Alfred Tennyson: "Tis better to have loved and lost than never to have loved at all."

Cheers to that, but what if we fudged a little bit and simply hired a specialist to erase the offending memories — scrubbed our romantic grouting, so to speak, with mnemonic Lime-Away? Wouldn't that be better? And maybe a prescription of Paxil to go with it?

Leave it to screenwriter Charlie Kaufman, the magnificently warped creative force behind "Being John Malkovich" and "Adaptation," to cook up such a wonderfully cock-eyed premise. Once again, Kaufman has found a strange, singular intersection between the classic and the postmodern, the timeless and the timely, and once again the result is funny, insightful and ineffably profound. It's one of the best love stories you'll ever see — crazy, unmedicated and every bit as messed up as heartache itself.

Off-duty funnyman Jim Carrey (“The Truman Show") brings just the right touch of neurotic longing to the role of Joel Barish, a lovesick loner in the classic Charlie Kaufman mold. "Why do I fall in love with every woman I see who shows me the least bit of attention?" wonders Joel, voicing world-weary anxieties that remind us of Nicolas Cage's desperate, shvitzing screenwriter in "Adaptation."

Joel's gloomy existence brightens considerably when he meets Clementine Kruczynski (“Titanic" star Kate Winslet), a vivacious if erratic young woman with an endless array of colorful quirks, including a fondness for temporary hair-dye (orange one day, blue the next) and a penchant for making art out of potato spuds. Joel and Clementine fall in love. Later, they have a fight. Afterward, Clementine pretends not to know Joel, or have any knowledge of their relationship.

Turns out, she's not faking it. Determined to start fresh, Clementine enlisted the services of Dr. Howard Mierzwiak (Tom Wilkinson from "In the Bedroom"), a neurologist who caters to heartbroken lovers and bereaved pet owners by selectively zapping the memories that plague them. As written by Kaufman, the procedure — which is performed in the patient's home, in his or her sleep — is an ingenious bit of pseudo-science that's almost troubling in its feasibility. "Technically, it's brain damage," says the doc. "Equivalent to a night of heavy drinking."

Stung by the loss of his darling Clementine, Joel elects to undergo the procedure, too — and here's where the idealism kicks in. Reminded of his love for Clementine, and infuriated by the fact that one of the doctor's techies, played by Elijah Wood (“The Lord of the Rings") is using his words and memories to woo her, Joel decides that loving and losing is better than never loving at all. Only one problem: The procedure has
already started, and Joel is unconscious.

What follows is like a psychology- themed hybrid of "The Terminator" and "Fantastic Voyage," as Joel doggedly tries to save Clementine by spiriting her away to parts of his memory where the doctor would never look for her, such as recollections of his childhood. French music video director Michel Gondry, who previously helmed Kaufman's "Human Nature," gives visually inspired life to Kaufman's ideas — at times, watching "Eternal Sunshine of the Spotless Mind" is like being transported into an M.C. Escher painting, with surrealistically repeating images and distorted planes.

Kaufman seems to be killing time with a sub-plot involving a nurse (“Spider-Man" babe Kirsten Dunst) and the medical assistant (Mark Ruffalo from "You Can Count On Me") who administers Joel's treatment, but their scenes together (raiding Joel's fridge and grinding on the couch like a pair of misbehaving baby-sitters) give the movie a welcome shot of light-hearted cheekiness.

Like few love stories before it, "Eternal Sunshine of the Spotless Mind" is equally in tune with the highs and lows of romance. The characters have their ugly, flawed moments, but therein lies the magic: Two imperfect people finding something perfect, at least momentarily, in each other. As groundbreaking as his previous scripts have been — you could make a good case that he's the most influential filmmaker of the 21st century — this one represents a step forward for Kaufman artistically. For once, he doesn't reverse field at the end and hand the thing off to ironic ambiguity. For once, he carries the play himself.