Lucy (that movie) is founded on a false urban legend.
Honestly, think about all of this:
- If we only used 10%, how come ANY brain damage has severe consequences? If we didn't use it/need it, then we could fully function without it. Brain damage and to an extent neurological damage would be less concerning if this was true.
- Brain scans show activities in all parts of the brain when any task, complex or simple, is done. You personally are just not aware of it, like you don't tell your heart to stop/go for example.
- The brain is the most complex organ in all vertebrates and some invertebrates, and more specifically, mammals. In less complex animals, like jellyfish, a brain is non existent. The simpler the animal, the smaller and less complex the brain. A simple enough organism does not need to do complex tasks, and relies only on their nerves to respond to stimuli. So if we only need 10%, why would it be so huge? Our brains would not be so huge if we only need 10% of it to function. We would have small brains if that were true.
- Around 20% of the bodies energy is used on the brain. Why would the body use so much energy just to fuel 10% of the brain's functions if this was true?
- ALL parts of the brain serve a function. Some do "more" and some do more "specified" jobs, but 100% of the brain functions to control something no matter how "small."
So, yeah. STOP IT! We use 100% of our brains like any other organism with a brain. We would not have "Godmode" awakened by "activating" the other 90% because we already use all of our brain's compacity.