The biggest mistake we make as journalists is to assume that trends continue. We know that the biggest stories come when there are dramatic reversals -- when the leaders of China, for example, renounce Marxism and set their country on course toward a consumer economy. But somehow we forget to factor the unexpected into our expectations.

At the start of a new year, it may be worth 30 seconds of your time, just for the mental exercise, to make your own guess on the unanticipated reversal of 1985. I know what mine would be: an upsurge in anti-business sentiment.

I say that in part because business has been riding high for so long now that it is due for a fall. The last few years have seen business taxes sharply lowered, government regulations steadily eased or entirely removed. Business has won victory after victory over unions at the bargaining table and in the political arena -- and has gained high standing with the public for itself as well.

The best-selling nonfiction book in America is the autobiography of the head of the Chrysler Corporation, Lee Iacocca. Time magazine's man of the year is another millionaire businessman, Peter Ueberroth, who showed you could even make big profits by running the Olympics on the principles of free enterprise.

As everyone knows, those whom the gods would destroy, they first put on the best-sellers' list and Time covers. It would not be surprising at all if the seeds of business' comeuppance were being sown in some of the present glorification.

The readers of Iacocca's book are learning, for example, that executives at Ford were eating lunches in their private dining room that cost the company $104 a head -- and were complaining at being charged $2 apiece for them, instead of getting them free.

Iacocca, who was fired from his job as president of Ford, says the culture of greed began right at the top, with Henry Ford II, who he says griped one year of paying $11,000 in income taxes, after going six years in which he paid nothing at all, thanks to the ingenuity of his lawyers.

He alleges that the company paid a $1 million bribe for a $29 million contract in Indonesia and says: "As soon as the press got wind of the attempted bribe, a full-scale coverup went into effect within the company. It was at least as impressive as anything that went on during Watergate. There was an internal purging of the files. There were even special meetings to coordinate excuses on why we did it."

Such tattling tears at the veil of respectability business has built around itself in recent years. But there are much more serious dangers in three other "T's": toxics, taxes and takeovers.

The turn of the year was framed by two stories of industrial disasters, the mass deaths in Bhopal, India, resulting from the toxic fumes leaking out of a subsidiary of an American-owned chemical company, and the asphyxiation and entombment of a score of miners in a Utah coal mine which had been pressing for a production record.

The Bhopal disaster was of unprecedented scale and, one hopes, unique. But there are bound to be human costs in the easing of government regulation of high-risk industries, from airlines to chemicals to mining. Anyone who doubts that does not understand the history of abuse of workers, customers and neighbors that brought on the regulations in the first place.

The tax issue, too, can turn against business very easily, as the smart business lobbyists in town understand only too well. When a Republican Treasury Department headed by a former Wall Street operator proposes a tax-reform plan that would raise the share of revenues paid by businesses, you can tell which way the wind is blowing.

Business cashed in on the tax-cut fever that swept America from 1978 through 1982, grabbing off a disproportionate share of the benefits of every tax cut from Proposition 13 right through the Reagan tax bill. It managed to reduce its overall contribution to state and federal budgets significantly, and passed the burden on to individual taxpayers.

But when President Reagan goes forward with his tax simplification plan, it will become clear that the major barrier to individual taxpayers' enjoying lower income-tax rates is the opposition of businesses, seeking to protect their own sweetheart deals. Watch what happens then.

The final "T" is for takeovers -- corporate raids. Free enterprise and entrepreneurship are very chic these days. But will they remain so, when people read that a T. Boone Pickens Jr. and his allies can pocket a quick $80 million profit by using borrowed money to attempt a takeover of Phillips Petroleum?

What does that -- or any of the other merger and takeover coups -- have to do with building a business, or creating new jobs, or anything but lining the raiders' pockets on a scale that makes the Ford executives with their $2 lunches look like petty chiselers?

If you ask me, business is asking for trouble -- and is likely to get it.