Despite widely published reports that Angelina Jolie was originally cast as the lead, but dropped out, Luc Besson has since denied them and admitted that he only met with a couple of actresses to discuss playing the lead role. He says when he saw how strongly Scarlett Johansson reacted to the story, she immediately landed the part.
The script took nine years to complete.
In an interview dated March 2014, Luc Besson said that this project took ten years to become a reality. Also, he admitted that he knew that some scientific assumptions were erroneous, e.g. that humans use only ten percent of their brains, adding nonetheless that such an assumption would be a great start for a sci-fi movie.
The primate seen in some scenes is Australopithecus afarensis, who represents the "missing link" between apes and humans. The skeleton which was discovered that exemplified this species was named Lucy after John Lennon's song "Lucy in the Sky with Diamonds." She lived 3.2 million years ago and is the earliest known hominid to walk upright like humans. The music which plays during the scene when Lucy touches the primate is entitled "Lucy meets Lucy."
The idea that humans only use 10% of their brains is a widely-circulated myth that has been debunked by neurological science many times over.
Luc Besson: a doctor in the Paris hospital with the other three drug mules arrested, later among those shot by Mr. Jang's gang.