Well, this explains everything. Scientists scientifically studied the brains of 29 people. Of those, 22 had normal brains while the other seven had a genetic variant that stops their brain from secreting something called a neurotrophic factor (BDNF). Without the BDNF, new memories aren't formed properly. And people with this gene variant also can't drive.
We've all seen them. Drivers so engrossed in whatever else they're doing that they don't seem to remember they are driving, too. Oh, how we've secretly wished there was a cop around to witness these acts and punish the offenders. Well, thanks to the wide availability of affordable cell phone cams, and the accessibility and popularity of the internet, motorists are taking the law into their own hands. Sort of.