What was going on when I was born?

The chairman of the Metropolitan Transportation Authority pledged yesterday to hold off increases in subway, bus and commuter fares until 1984 if the State Legislature acts to close the authority's $300 million operating deficit. ''This is a rotten time for a fare increase,'' said the chairman, Richard Ravitch. ''The economy is lousy, and the service is poor. I would rather see the fare increases delayed until the economy gets better and we can see improvements in the M.T.A. system.''

As recently as early 1981, the managers of the General Motors locomotive plant in the western suburb of LaGrange were overflowing with optimism. Production was near capacity as railroads ordered the latest in energy-efficient equipment. The long decline of the rail industry had halted. The gains in piggyback traffic had stemmed the loss to truckers. Coal was again moving in vast quantities to the electric utilities. Railroad profits and cash flow were improving, thanks to greater pricing freedom under deregulation.

The Congressional Budget Office has concluded that President Reagan's $26 billion plan to deploy MX missiles would make ''a relatively small'' contribution to the nation's strategic capabilities. The debate over the new missiles intensified today, with Senator Henry M. Jackson, Democrat of Washington, criticizing the President's plan for deploying them and Defense Secretary Caspar W. Weinberger defending it as effective and necessary to deter attack. Mr. Jackson, a member of the Senate Armed Services Committee and a longtime advocate of strong national defense, said the closely spaced basing plan, known as ''dense pack,'' was in ''deep trouble'' with Congress. Security of Basing Plan Further, he said that discussions with experts inside the Pentagon and outside the Government who specialize in Soviet nuclear weapons and tactics led him to believe that the basing system would be secure against Soviet attack for only four years.

Steven J. Ross, chairman of Warner Communications Inc., has played the role of the missing star in a criminal trial involving the company's purchase of stock in the Westchester Premier Theater. Warner's assistant treasurer, Solomon Weiss, was the only defendant in the trial, which ended with his conviction on Saturday in the Federal District Court in Manhattan. Mr. Weiss was found guilty of participating in a fraudulent scheme for Warner to buy stock in the Westchester theater as part of a ''pattern of racketeering.'' Much of the attention in the trial, however, focused on Mr. Ross, even though he was not charged with any crime and did not even appear as a witness. Several other Warner executives testified, including two former executives who appeared as key witnesses for the prosecution.

year-old filly ever, died of a viral infection early yesterday morning at Santa Anita Race Track in Arcadia, Calif. Landaluce had raced only five times and only in California, but she had won the enthusiasm of racing fans everywhere because her brilliant speed suggested that she could beat colts as well as fillies. Also, she was one of the first daughters of the popular Triple Crown winner Seattle Slew, making her an extraordinarily valuable potential broodmare. Landaluce's death continued a tragic pattern of injury and illness that has plagued the fastest horses in training this year. Timely Writer, the early favorite for the Kentucky Derby, barely survived an intestinal infection that knocked him out of the Derby, then was humanely destroyed after shattering his left foreleg in the Jockey Club Gold Cup last month. Various leg injuries and racing accidents this year prematurely ended the careers of other potential champions, including Conquistador Cielo, Perrault, Hostage and Stalwart, all of whom were saved for breeding.

In a year of red ink and belt-tightening for cable television programming networks, at least one network appears headed for success. Music Television, or MTV, a round-the-clock music channel, has tripled its audience in the last year to 6.7 million households. Although it is still losing money, it appears on its way to becoming one of first advertiser-supported cable programs to make money. MTV's growing popularity has raised some questions about cable television programming. MTV is becoming so important in airing new talent and in helping to sell records -for a business badly in need of a boost - that performers of many different kinds of music want to appear on the channel. But MTV plays only one particular type of music - a contemporary form of rock and roll known as album-oriented rock, or A.O.R.

Almost a century ago, Julian Alden Weir, carrying his oils, brushes and canvas, would set forth into his farm here. He jokingly called the land ''my unprofitable rock pile,'' but its soft beauty inspired some of his most famous paintings. Now - as the Metropolitan Museum of Art prepares a major retrospective of the American Impressionist's work - a dispute has broken out over whether to preserve the farm because of its role in Mr. Weir's artistry. Sperry Andrews, who owns Mr. Weir's former home but not the adjacent 100 acres that were his farm, wants to save the land as a memorial to the artist. But the men who do own the land intend to build a housing subdivision on it, a plan the Town of Wilton agreed to nearly 20 years ago.

A conference of 88 nations reached a consensus this morning on ways to strengthen the world trading system, although differences remain between the European Economic Community and other countries over subsidized competition in agriculture. Deadlocks between the United States and the 10 Common Market nations and between developed and developing countries were broken after a world trade conference went into extended session this weekend under the chairmanship of Canada's Deputy Prime Minister, Allan J. MacEachen. The conference of trade ministers had been teetering on the brink of failure since it opened Wednesday. Collapse would have intensified economic nationalism and protectionism at a time of growing unemployment and debt strains on the world's delicate financial mechanisms.

If Switzerland's delicate economy has been described as a finely tuned watch, then something seems seriously wrong with what might be called its mainspring. From one point of view, ''the watchmaking industry is in a fundamentally healthy state,'' as Ulrich Spycher, chairman of Societe Suisse pour l'Industrie Horlogere, the group that makes Omega, Tissot and, in the United States, Hamilton watches, said in a recent interview. Indeed, Swiss watchmakers, in the rugged Jura Mountains, have managed to remain at timekeeping's technological cutting edge, and exclusive houses - like Piaget, Patek Philippe and a dozen others that produce luxury timepieces for the gilded set in New York or Riyadh, Saudi Arabia -are flourishing. Last year, the industry shipped $2.1 billion worth of watches abroad, more than 90 percent of production, according to Theo Radja, chief economist at the Watch Industry Association here. Their high added value, he said, puts them among Swiss industry's most lucrative foreign exchange earners.

''Obviously I used this opportunity to brief the Deputy Prime Minister.

Major trading nations reached a consensus early today on an agreement to strengthen world trade and limit restrictive export competition. But despite the trade ministers' declaration in Geneva, differences still remained between members of the European Economic Community and the principal farm exporting nations, including the United States, over agricultural subsidies. (Page A1.)

California is making sweeping changes in its system of medical care for the poor in an effort to lower the cost of treatment by using competitive bidding. Supporters predict that the changes, established by a new law, will increase efficiency, eliminate waste and lead to the development of new cost-cutting concepts by hospitals, physicians, dentists and others who provide medical care. Organized medicine and some hospital administrators, however, say competition will lead to second-rate care for the indigent. The California plan is one of several innovative approaches proposed in the West, though it differs sharply from a competitivebidding proposal embraced this fall by the Reagan Administration in an effort to control costs of the Medicare program, which provides for the aged. But all the proposals share a common goal: reducing the soaring health care costs paid by the state and Federal governments.