Many still believe that we only use about 10 percent of our brains, even after science has proven otherwise.
Many sources of this misinformation appear to point to an American psychologist of the early 1900s named William James, who said, "the average person rarely achieves but a small portion of his or her potential." The media has long perpetuated that into "only using 10 percent of our brain".
In addition to those 100 billion neurons, the brain is also full of other types of cells that are continually in use. We can become disabled from damage to just small areas of the brain depending on where it's located, so there is no way that we could function with only 10 percent of our brain in use.
Brain scans have shown that no matter what we are doing, our brains are always active. Some areas are more active at any one time than others, but unless we have brain damage, there is no one part of the brain that is absolutely not functioning. Here is an example. If you are sitting at a table and eating a sandwich, you are not actively using your feet. You are concentrating on bringing the sandwich to your mouth, chewing and swallowing it. But that doesn't mean that your feet aren't working -- there is still activity in them, such as blood flow, even when you are not actually moving them. Also true - alcohol does not really kill brain cells.