If The brain is like a sponge then it is most probably going to absorb some dirty water especially in our society. Therefore it is vital to give it a good ring out regularly. Even Einstein said whatever has been proven will one day be disproven so the water that once was clean will become murky. There are numerous cleaning products for this purpose...natural and man made....for heavens sake people...u can forget to scrub behind ur ears this beautiful weekend...but don't forget to give that magic sponge a good ring out.