Gondry’s style creates an analogy for what happens when a person’s memories begin to disintegrate or disappear, in the all-over, “global” sense (Alzheimer’s), as well as for the fleeting universal experience of struggling to remember a name, or some aspect of a dream, and somehow managing to grasp a sliver of it, only to see it slip away and vanish. 

The movie also somehow captures that awful knowledge that the personal dramas which consume us go unnoticed by almost everyone else. When it came out, the movie felt so immediate that it was as if you were seeing something that was actually happening, out in the physical world. It still feels like something that could happen because of how it’s lit and filmed. The action seems to have been captured entirely in real locations even when the actors are on sets. The locations tend to be unglamorous, with the notable exception of the beach at Montauk where Joel and Clementine first met (there’s no way to make a beach seem anything less than majestic). The ordinary magic that constantly happens inside each of us – the staggeringly complicated interplay between present-tense observation and interactions; the stabbing intrusions of memory, fantasy, and trauma – contrasts against boringly regular urban and suburban settings that seem to have been chosen because they are the human equivalent of the featureless mazes where rodents of science reside. When Joel and Clementine race through memory spaces where Joel has hidden memories of Clementine to prevent their erasure, they scamper and stop, twist and change direction. They’re people in a mouse-maze.

There’s also a fascinating matter-of-factness to the way the film presents the interactions of Joel and Clementine and the (largely unseen) team of memory-erasers (headed by Tom Wilkinson, and including Dunst, Mark Ruffalo, and Elijah Wood; what a cast!), as well as the way the film un-peels the layers of casual corruption surrounding the process by which memories are destroyed. When you have access to a memory erasing machine and no legal or ethical oversight, the tech is bound to be abused. Is there even an ethical way to use it? Is it right to simply erase something traumatic from a person’s brain? Is it better than teaching the person how to process, understand, and transcend trauma?

There’s a scene at the end of 1981’s “Superman II” where Superman erases Lois Lane’s memory with a super-kiss to protect his secret identity as Clark Kent. The moment was viewed by most audiences at the time as a fairy tale flourish, along the lines of Superman turning back time to save Lois at the end of the first movie. Today it would be considered a non-consensual mental assault, like a roofie. “Eternal Sunshine” sometimes plays like a speculative drama about what would happen if it were possible to replicate Superman’s kiss and turn it into a service that people could pay for. No good could come from such a thing, which is a sure sign that some company out there is hard at work inventing it while its CEO chases billions in startup money from venture capitalists.