[...] let's start with the enticing premise of Luc Besson's "Lucy," starring Scarlett Johansson: [...] it turns out, in real life, humans pretty much DO use their whole brains. The more relevant question, though, is how much of your own brain you should use when watching "Lucy" — a truly bizarre if often entertaining romp through, hmm, well, neuroscience, biochemistry, anthropology and basically the entire human experience, in 90 minutes. Just how much of his brain did Besson access when writing the dialogue?