Never wear brown shoes with a blue suit.
Take off your hat when a lady enters the elevator.
A gentleman ties his own neckwear.
Wear Panama hats and seersucker suits between Memorial Day and Labor Day.
Or so I was brought up to believe. Today, most men don’t wear hats at all, though it would be nice if they would take off their baseball caps in restaurants. Fewer men wear ties at all. These rules for gentlemen (I dare not presume to speak for the ladies) are already archaic. They represent the kind of principles that my older sister once dismissed impatiently as "silly little rules that nobody else knows or cares about."
To these "silly little rules," add many of the rules or principles of grammar and usage. You don’t have to make subjects and verbs agree, or pronouns agree with their antecedents. You can put chocolate in a cocktail and call it a martini. You are free to chew with your mouth open. This is America.
Except that there are still some people to whom precision matters. The Sun recently ran an article that referred to "military court-martials." Well, who else but the military conducts a court-martial? And the proper plural is courts-martial. We have a lot of military personnel among our readers, and at least some of them, reading that phrase, may have wondered, "Do their reporters and editors know their business?"
Precision matters to some readers, and those are the readers — literate and informed — whom we ought to prize and cultivate. The reader who is unaware of nice distinctions of meaning will sail through without noticing (If you wear no hat, there is nothing to doff when a lady enters the elevator). The informed reader will hold the publication in respect.
Here are a few examples of useful precision in usage.
Anxious/eager. To be anxious about something is to experience anxiety, jitters, apprehension. To be eager is to have an enthusiastic anticipation. If you are anxious to see the morning paper, you are worried about what is in it. If you are eager to see the morning paper, you expect good news.
Enormity. Not an enormous thing but a dreadful thing. The word may suggest scale, but it has nothing to do with physical size. The Holocaust and Stalin’s purges are enormities. The Mall of America may be huge, but it is not an enormity (except, perhaps, in aesthetic terms).
Fulsome. Not full of or abounding in, but nauseatingly excessive. Fulsome praise is not merely ample, but the kind of flattery that only the vainest can swallow without gagging.
You can misuse these words, and many others, and the literate reader will gather your intent in context, but you will sacrifice respect.