Well after being a manager, I can say that it is actually a different animal. I know that employees always think for them to be properly managed, their manager needs to be able to do their jobs, but actually, that is backwards thinking.
A good CEO that is running a car company, does not need to know how to put an engine in the car for instance. A direct superviser, at least a good one, does not need to know how to put that engine in a car either, but what he does need to know how to do it motivate people and support their people to be successful.
I know it sounds odd to many people, but the sooner you grasp that concept, the sooner you will be able to be that person that does not know how to do the job you are supervising, and face it, being the worker bee is not where the money is!