The movie Lucy which made $463.4 million is kind of based on an urban myth that an average human uses only about 10% of the brain capacity.
It is simply not true. Many of us believe this without even trying to find out if it is true (and by many I mean most of us, even some of my friends who will be doctors soon).
We use most of our brain most of the time.
Harvard psychologist William James once said that people only meet a fraction of their full mental potential which later got stuck with 10% figure.This is considered as the origin of the urban myth.
The truth is we use 100% of our brain.Shocking right?
The technologies like fMRI and PET are used to prove that for sufficiently complex activity most of the brain is used. Its just like our other muscle groups, we might not use them simultaneously but you do use them to the fullest.
So basically we might not use our complete brain at once but we use 100% of it for most of our activities.
Also it is said if humans use only about 10% of their brains then after a minor trauma or injury to the brain (to the so called idle 90% of it) there should be no change in their behavior. Well, that is not the case. Most of the people who suffered brain injuries are left impaired in some form.
And one more thing, an average adult human brain which is about 2-3% of the body weight, uses about 20% energy, thus it would make evolutionary sense to get rid the idle part of our brain that is using that much energy over time. But, it is still there!
So basically we use our complete brain in our day to day life.
I’m really sorry in case you were waiting for some drug to manically increase your brain use to 100% and get some badass powers like Lucy.