We live in a world of specialization.
The person with a doctorate may well be eloquent but ignorant when speaking outside of his or her field of study. Graduate schools contain some of the brightest and dumbest of our citizens and, depending on the subject, those qualities may be found in the same person.
When it comes to advice, we are not far from the days where we bought thread in one shop and needles in another. Our consulting firm often gets referrals from attorneys with clients whose problems stem more from management fumbles than from legal ones. We, in turn, send people to law firms or to mental health professionals and other specialists.
I've seen some cases where the best strategy is to get the experts together in the same room in order to work out a comprehensive approach rather than bounce from source to source for six months or more. Doctors are ahead of other professionals in adopting that technique.
This simply recognizes how various subjects connect. It is difficult to grasp certain situations without some knowledge of law, psychology, history, economics, language, management, and more mixed in with a bunch of street smarts. Even then, we may be reaching in the dark.
Learning the potential connections is a marvelous way to foster humility.