Workers are hired to do one thing: work. You instruct them on what you want accomplished, and it is their job to get it done. You don't need to know how anything is done. They are being paid to do it for you. Competence in the work is for the hired help, not the head honcho calling the shots. If the boss was competent enough to do the job himself, why would he bother paying someone else to do it? The PHB's skill is in keeping the peons in line, not in knowing how to get things done for the company.
The truth of this idea becomes even more apparent in the context of the globalized economy. With cheap overseas labor, there's no point in you as the PHB knowing how to do anything. It's far cheaper and more effective to outsource to foreign workers (which is another topic for a future discussion). It would cost more time and resources for you to gain competence than it would be to just hire a foreign worker to get things done.
So, now it's no longer a secret. I've revealed the essential key to my pointy haired success. Competence is not required.