I also agree that it is always nice to know your airplane well, but for the flight safety aspect, deeper knowledge than the easy to remember basics of the fligt control laws I mentioned above is not necessary to be a safe pilot.
Studi, I don't think it is possible for me tell you how strongly I disagree with what you said there. The requirement for Professional Pilots (see name of forums and community where this discussion is taking place) is a degree of care well beyond what you assert.