Often the answer is known--by somebody, somewhere -- but life is too short to ask the question or follow it up.

The French flag, for example. There must be a lot of people who know what the royal standard looked like in the time of Louis V. As it happens I would like to see that banner. The way to find out, no doubt, is to write a letter to the Bibliothe que St. Genevie ve since the embassy, the Library of Congress and a few other sources here are quite weak on flag facts. There must be books on French flags since Clovis?

Here, as so often, the truth seems not worth the bother. You persuade yourself you never really wanted to know. Now that the Library of Congress is efficiently computerized, it's a wonder you can find out how to spell fudge from them. My dealings last year on the Brooklyn Bridge were entertaining. They were able to provide a volume of minutes on the Bridge Commission of a century ago (a rare and useful book) and nothing else. Unless you count a volume on a different bridge and a picture book for kids, which also spewed out of the computer.

Very likely they have more than one book, and there are probably a dozen laborers in that vineyard who keep a considerable bibliography of the bridge right in their heads, but you never get to them since the stupid computer keeps bouncing up, "I can handle it." So much for American efficiency and library research.

Another day, not trusting computers to retrieve as well as a labrador who flunked field school, I went to the great catalogue to find stuff myself. The computer was down and please come back. I did. The topic was William Robinson, the great Victorian gardener. Some of the books in the catalogue were "not on the shelves" and probably haven't been since 1902, but Not On Shelf is code for Go Get Lost.

People who do not use great libraries go through life thinking they "have everything," and great libraries love to remind you they have 23 publications on the goats of Afghanistan, etc. The trouble is if you don't need the goats but some exotic topic like Brooklyn Bridge or William Robinson you may be in for a jolt.

I mention this only to reinforce the point that the answer is clearly there somewhere, but not necessarily retrievable short of sending in troops.

Recently I read in The Guardian and The Times about this horse, Sefton. He is one of several horses and men caught in an explosion a while back set off by Irish terrorists in London. Some died and some were grievously hurt, including Sefton who had a 50-50 chance to live and took it, to the satisfaction of his many friends. He has turned 2l and retired from military life to pasture in a retirement farm run by Col. Tweedie. His old rider, a young-looking corporal, accompanied him, and the papers showed them kissing. Sefton was, not to split hairs, a lousy horse always at the bottom of his class. Once he threw his rider with the queen of England looking on, and was reduced to carrying only recruits (if they get brained, no great investment is lost).

But even if he wasn't much of a hero, people followed his recovery with interest. He got plenty of get-well cards and all that, plus "250,000 Polo mints."

Somebody must know what Polo mints are and why the hurt horses got 250,000 of them, so I asked my wife, who commonly knows about these things.

The mints are the kind you buy at newsstands, she said, and probably the corporal once said Sefton didn't like apples but adored the mints, so people sent him a lot.

That is plausible, but not necessarily true. In the reporter's trade you pay no attention whatever to what is plausible, but get to the bottom of things or at least hang the alleged facts on a sheriff, not your wife's plausible guess.

I started to phone The Times or The Guardian, but my courage failed. I know how the conversation would go:

Murchison here. What? Please excuse me. The Lord only knows why they connected you to me. I don't know anything about the horse or the mints. I'm up to my butt in a story about Margaret Thatcher's plans to invade St. Edward's Island and Honduras in a two-pronged attack. We think they are nowhere near each other and have been inquiring four days now from the British Library. They are working on it. Sorry, I simply don't have time for Sefton and the mints. Do you mind if I ask who the hell cares?"

It is always embarrassing to say I do, more than about Mrs. Thatcher's sallies.

We who have experienced the world in its amazing richness do not just assume some plausible thing about Sefton not liking apples. It may have nothing to do with Sefton personally, but may be an ancient custom of the realm that an old horse, or a military horse, or a wounded horse, gets Polo mints, as sailors used to get their ration of grog. The custom may date from the reign of Edward I, or Bosworth Field or Agincourt or Cre'cy or Injah. How stupid you would feel if that were so and you had suggested it was because Sefton didn't like apples.

All over England, and probably all over Washington, there are people who know the truth about the wild outpouring of mints. I would know also if I spent the best four years of my life finding out.

Some reporters, not those at this newspaper, knowing they do not know and knowing they are too lazy to find out, simply avoid the issue. Never will "Polo mints" escape their lips. Others, equally indifferent to practical results, will phone the Library of Congress, the British Tourist Authority, the White House or other dead ends and forget it.

They escape reproach by never raising the subject. Or they say that diligent researches have not produced the answer, but that only means they phoned the Library.

Others know in a flash when they have come across something They Really Have Got To Know and promptly record it. It is shameful to raise questions you cannot answer, but some of us weigh everything including our ignorance and still forge ahead. To be called "incompetent ass."

But I feel you should be told. Sefton's mints are incomplete, but at least you know he got God's plenty of them.

The full answer is out there somewhere. Gallipoli, did they give mints at Gallipoli? Col. Tweedie or the corporal would know or know how to find out. Once you got hold of them.

But we live in an imperfect world, full of accountants and other dragons. About the tenth time you phone Paris about the flag or the twelfth call to London about equine customs of the l2th century (just to be sure) the question arises whether it's worth it.

In this way truth is shoved right out the house, and this is why we have to read about Reagan-Mondale debates and other wonderland stuff posing as urgent fact. While truly significant things like Sefton's mints get swept under the rug as if they were trifling.

When these things come up, someone should be sent to investigate. In London I could do it within the week, never darkening the British Library's door. Then on to Paris. Because I know what will stick, in human history, and what won't.