The truth is that we use virtually all of our brain every day.
Let's say, for example, that as you are reading this article, you are eating a sandwich. As you are reading, the frontal lobes in your cerebral cortex are engaged in thinking and reasoning. You are enjoying your delicious sandwich thanks to your parietal lobes, which are responsible for taste, texture and smell of food. The occipital lobes help to process how you see the words on this page, and the temporal lobes help you process what you hear—like the crunch of your sandwich and the rustle of the page.
That's what I basically wanted to say: That we already use all of our brain and that the 10% are a myth.