It is unfortunate that people still claim that we only use 10% of our brain. However, it is likely that the claim will persist as the 2014 movie LUCY has Morgan Freeman reinforcing the claim. While it may be true that some people only reach a small fraction of their potential, it only confuses the understanding of the brain to claim we only use 10%. This entertaining video (4min) does a nice job of challenging the claim.
Misinformation regarding the brain is in no short supply. The most common misinformation is likely regarding the hemispheres of the brain. This stems from the popularity of the topic in the 70’s and 80’s driven by the first split brain operations. In this RSA animation, Iain McGilchrist revisits the divided brain with newer insight debunking the most commonly heard myths. However, what he brings to the table is a new understanding that may prove more interesting than what is most frequently presented.