Re: This one time...
That is exactly the point of the seemingly ironic "But what do I know? I'm just a brain surgeon." statement in the Volvo advert. Most people don't need to know how a tool like a car or a computer works, just be competent in using it. If someone is really smart or challenged in their occupation, they may even be incompetent in other areas, they should be competent in, because they have neglected them.