I'm confused. Your first paragraph contradicts what is stated in the second. Either way, the claim that we only use a small fraction of our brain is obviously nonsense when we accept that the brain has many different parts that are all involved in performing different tasks in a healthy human being. The brain is a very 'needy' part of the body. It's enclosed inside a skull comprised of bone tissue and receives a nutrient-rich blood supply direct from the heart.
RE: People use only 10 percent of the brain