Finish last in your league and they call you idiot. Finish last in medical school and they call you doctor.
You know what they call the fellow who finishes last in his medical school...
Sometime they don't let you know that they know that they don't know...
In garden arrangement as in all other kinds of decorative work one has not only to acquire a knowledge of what to do but also to gain some wisdom in perceiving what it is well to let alone.