For the record I confess that I have not yet watched “Lucy”, nor seen the trailer (I generally avoid trailers as they tend to give away too much, leaving nothing but “Ah, yeah, I’ve seen this already” for the actual movie — which is why I haven’t bothered to watch “Pompeii”; thanks, Hollywood, for ruining that for me), nor do I know whether I will watch it, except that it has Scarlett Johansson and Morgan Freeman in it which tends to be compelling incentives, but if I do watch it, I will keep in mind that it is just a movie. It may be science fiction, but that is still just fiction.
Yesterday I watched “Edge of Tomorrow” and enjoyed it immensely (★5 just for having me constantly on the edge of my seat), but I didn’t actually believe in it.
However, do read this article; not necessarily as a critique of the movie, because we’re already aware of Hollywood’s take on science, but because it may tell you something about our brains that you didn’t already know, and about the claim (which far predates this movie) that we only use a few percent of its capacity (and that there is an unimaginable untapped potential for mental superpower) because, apparently, that’s just not so.
And, by all means, watch the movie if you like. At the very least you will get to see Scarlett Johansson and Morgan Freeman.