Luc Besson's Lucy is a movie about a woman who can access 100 percent of her brain that asks you the viewer to use less of yours. The premise is based on the oft-repeated fallacy that humans only use 10 percent of their brains, and if we could only harness our full capacity, we'd be enlightened gods. Not only is this untrue (virtually 100 percent of a normally functioning brain is used for some aspect of cognitive, motor, or involuntary functioning), it is a cliché. There are dozens of examples on the "90% of your brain" TV Tropes entry of pop culture that reiterates this bogus claim. Lucy, in which large doses of a synthetic form of CPH4 cause the brain of Scarlett Johansson's titular protagonist to expand, then, is not so much sci-fi as it is fi-fi.
Accepting it as such, though, requires even more suspension of disbelief. The task is downright herculean. After Lucy is infected with expanding awareness, via a bag of CPH4 that has been surgically implanted in her abdomen for the sake of drug trafficking she is forced into, she walks into a hospital brandishing a gun, which doesn't…seem so smart? She bursts into an operating room, reads the patient's brain X-rays, and shoots him right there on the operating table, explaining to the doctors that he was going to die anyway and since she can make it, they should operate on her. Even if you accept that her mind was expanding, she still has no apparent intimate knowledge of neuroscience—no matter how many terabytes you have at your disposal, a hard drive is just a hard drive until you fill it.
The movie charts Lucy's mind expansion over time, as she ingests more of the CPH4, but her development is haphazard. I found it hard to follow. How is it, for example, that she psychically knows the name of a cop she calls to help her hunt down the drug ring's CPH4, as well as the color of the pen next to him, but that she has to tap into a specific cell phone signal (represented by vertical lines that extend down from the sky and can be expanded with the reverse pinch one does on an iPhone screen) to find out the drug kingpin's whereabouts?
Inconsistencies and a failure to adhere to even its own made-up logic plague this tight little tale of superheroic nihilism that would be much less dumb if it didn't feel the need to explain why the superhero is the way she is. For that, it is pretentious and dumb, although it is not without its charms. It zips along with such velocity, the resulting g-force helps distract from its inanity. Visually, it's terrific—there's a tremendous scene on a plane where Lucy's skin starts to disintegrate from her face and eventually turns into a powder that spreads through the air like sand on a windy day. Apparently, this is what happens when CPH4 starts running low in one's system, or something—the movie just makes sure that Lucy stays well stocked for the rest of its duration. Scarlett Johansson does her detached, matter-of-fact robogirl thing that she almost always does, especially outside the confines of strict realism. Morgan Freeman, a brain expert, pontificates like he always does, his booming voice rewriting nature's laws as though he is god himself.
A fundamentally incorrect movie about elevated brain capacity, you can reject Lucy outright or get on board and dumb yourself down. That latter scenario creates an interactive experience in which you operate at a lower level than the film, giving you a working example of the divide between normal brains and Lucy's brain that the film devotes itself to. During a lecture early in the movie, Freeman's character offers, "Ten percent might not seem like a lot but look at what we've done with it." Yes indeed. Soak it all in.