Limitless - what if a person used more than 10% of their brain?

One of the very cool films that came out in the 2010s was The Darkness, or Limitless in the original. In addition to the cool plot and ambiguous morals, it has a lot of visual and compositional choices that became more popular later on.

Limitless is an adaptation of the novel originally titled The Dark Fields. It is a 2011 American techno-thriller film directed by Neil Burger and starring Bradley Cooper, Abbie Cornish and Robert De Niro. The film is based on the 2001 novel Dark Fields by Alan Glynn, with a screenplay written by Leslie Dixon. The film was released in the US and Canada on 18 March 2011, and in the UK on 23 March 2011.
Budding writer Eddie Morra suffers from chronic writer's hunger, but his life changes instantly when an old friend introduces him to NZT, a revolutionary new drug that allows him to unlock his full potential. Eddie can remember everything he's ever read, seen or heard, learn any language in a day, understand complex equations and charm anyone he meets, as long as he keeps taking this untested drug.

Soon Eddie takes over Wall Street, turning a small stake into millions. His successes attract the attention of mega-mogul Carl Van Loon, who invites him to help organise the largest merger in corporate history. But at the same time Eddie attracts the attention of people willing to do anything to get their hands on his stash of NZT. With his life in danger and the drug's brutal side effects driving him to desperation, Eddie dodges mysterious stalkers, vicious gangsters and an intense police investigation as he tries to keep his dwindling supply alive long enough to outsmart his enemies.

Let's analyse what storytelling techniques are used in this film:

How We Got Here: At the beginning of the film, Eddie Morra stands on a high ledge and remembers everything that brought him here. Quite often films start at some dramatic point and then deal with exactly how the hero got to that point.

Book Ends: The film begins and ends with Eddie and Lindy in a restaurant.
Main Device
Colour Wash: It is used intentionally when someone is on NZT. When a person is on NZT, the colours are brighter and more contrasting, showing their heightened self-awareness, while outside of NZT the colours are natural and dull. I think this is the most important technique here.
This film definitely has a broken moral. The main character takes drugs, and we're sort of told that drugs are bad, and shown all the bad consequences of their use. But at the end of the day, the main character is fine, and he keeps taking drugs.

What happened to the mouse? It's a technique where some plot arc just takes and disappears from the narrative. Here it's a blonde girl who turns up dead, and in the end it's never clear who killed her or why.

Chekhov's Guns:

- In the opening scene, Eddie watches a film with Bruce Lee. Later in the film, he uses techniques from that film to defend himself against some punks.

- At the very beginning of the film it turns out that Eddie can learn languages by simply listening to how they are pronounced. In the film's finale, this skill comes in handy when he has to trick a blind Russian gangster into shooting his friend.

- Eddie makes some stupid decisions for a guy with a four-digit IQ, even though the pills apparently give him a sense of invulnerability. This makes sense, since pills increase intelligence, but not wisdom.

- Eddie could have avoided a lot of problems if he had just paid off the Russian loan shark as soon as he had the money.

- Moreover, even before taking the second pill, he realises A) that there are people who would kill for those pills and they may know about him, and B) that he has a limited supply of pills and doesn't know where to get more. Despite being a super genius, he apparently doesn't even care about these problems and how to solve them until he's forced to. It's more important to drive a Maserati fast.

And here are a couple of interesting facts:

A scene in which Eddie speaks Chinese to a waiter in a Chinese restaurant has been heavily criticised as the characters simply speak in gibberish.

In the beginning, when Eddie is a slacker author, he wears his hair half-long and uncombed. When he starts taking NZT and becomes a genius playboy, he changes his hair to shorter and trendier. At the end, when he runs for Senate, he changes his hair again to a short, conservative, business-like hairstyle.

Eddie quadrupled his money every day. The first day he started with $800, the second day he got $2,000, and the third day he got $7,500. He said it was going "too slow" and the next day he went to borrow $100,000 from a loan shark. However, if he kept doing what he was doing, he would quadruple his 7.5k the next day and get 30k and then 120k the next day. By taking this loan, he saved himself one day. If he had kept his head down the whole time and played the stock alone, he would have made $120 million in a week from the day he decided he needed to take out the loan, without actually having to take out the loan. Apparently none of the authors understand what exponential growth is.
The original, darker ending of the film, closer to the source material, was changed after it failed (combined with the fact that the writer and director didn't like it). In this ending, it is revealed that Eddie is still on NZT and his stash won't exist forever, making Carl's possession of the supplies in the future that much more threatening. At the end, Eddie tells himself that he needs to find a way to quit drugs.