What was going on when I was born?

New York City's Transit Authority is not legally required to protect a passenger from crime in the subways or to supply additional police protection to known high-crime areas in the system, the State Court of Appeals held yesterday. The unanimous decision by New York State's highest court, written by Judge Bernard S. Meyer, extends to the Transit Authority police force a degree of legal immunity already enjoyed by other uniformed police forces in the city. The judge expressly rejected contentions that the Transit Authority should be held to the same standard of care that is required of private bus and railroad lines. ''That a nongovernmental common carrier would be liable under the same factual circumstances is not determinative of the authority's liability,'' Judge Meyer wrote. ''Its immunity rests upon the same considerations as does the immunity of a municipal or other government body from liability for failure to provide adequate police services.''

Small arts organizations and avant-garde groups, which rely heavily on Government money, appear likely to suffer most from budget cuts being proposed by the National Endowment for the Arts. In some cases they may be forced to close, according to cultural leaders interviewed around the country. The endowment's 1983 budget, recently submitted to Congress, calls for $101 million, compared with this year's $143 million, and the indications are that the cuts are being felt most strongly in nonprofit theater. Some groups have curtailed some of the most important parts of their operations - the creative part that deals with new playwrights, new plays and innovative productions. Not only will creative effort slow down in the theater, but many performing-arts institutions, faced with inflated budgets, falling attendance and the endowment's cuts, say they will tend to play it safe, relying on sure-fire box-office hits and refusing to take a chance on experimental works, which almost are always box-office failures.

Thomas Estes, the oldest son of Elliott M. Estes, the former president of the General Motors Corporation, stood before a Federal magistrate today and pleaded not guilty to charges that he used his family name and false documents to extract millions of dollars from local banks and business associates. Mr. Estes, who is 43 years old, was indicted earlier this week on 10 counts of fraud and misrepresentation in connection with his financial maneuverings, which he reportedly resorted to in an effort to live elaborately on a moderate income. His tactics, according to local news accounts, consisted mainly of paying old debts with new, and larger, borrowings, most tied to nonexistent deals. Thomas Estes refused yesterday to answer questions about the charges. His father has declined commented since the beginning of the proceedings.

The International Trade Commission today rejected more than half the cases brought by the domestic steel industry in its filings of unfair trade complaints against steelmakers from eight European countries and Brazil. However, in its preliminary findings the Government's quasijudicial trade investigative agency kept alive 38 of the 92 cases on the ground that these cases involved imported products that may be causing injury to American producers and their workers. The petitions, seeking sharply higher duties that could bar much European steel from the American market and lead to higher steel prices, were brought last month by United States Steel, Bethlehem, Republic, Jones & Laughlin, National, Inland and Cyclops. The steel producers named in the complaints were from Britain, France, West Germany, Italy, Belgium, the Netherlands and Luxembourg (all members of the European Economic Community), Rumania and Brazil.

The Mexican peso was abruptly devalued by about 30 percent today after the Government announced it would no longer intervene on exchange markets to support the currency. The move was surprising only in its timing since most bankers had forecast a major devaluation later this year. It was apparently brought on by a new flight of capital and mounting speculation against the currency. The Bank of Mexico announced late Wednesday night that it would allow the peso to float freely until it found a level ''corresponding to current economic conditions.'' The central bank was ready to prevent a disorderly market but would not impose exchange controls, it said.

The Comptroller of the Currency, in an unusual private letter and report to Citibank's board of directors in December 1980, expressed concern about some of the bank's trading in foreign currencies and said that certain of its accounting and audit procedures raised serious questions about Citibank's safety and soundness, according to Government documents and officials. The Comptroller's office, which regulates nationally chartered banks, criticized Citibank after a long staff investigation into the bank's practice of shifting foreign exchange profits from countries with high taxes to tax havens. It did so through contrived transactions between various Citibank branches, Government investigators have found. John G. Heimann, who resigned last April as Comptroller, supervised the Citibank investigation with the assistance of the enforcement and multinational divisions.