What was going on when I was born?

The Hilton Hotel in New York is losing 25 percent of its foreign clientele to cancellations. Worse, at the city's five Sheraton hotels, three out of four overseas tour-group reservations are noshows - twice as many as last year. And Thomas Cook & Sons, the British travel agency, notes a ''significant dropping-off'' of overseas tours to the United States. Why the cold shoulder? The reasons are purely economic, says Jorgen Hansen, Hilton's general manager. ''The exchange rates have gone out of sight for some of these people,'' making foreign travel much more expensive, he said.

Twelve years ago yesterday Morty Manford was 18 years old and a patron in the Stonewall Inn, a homosexual bar in Greenwich Village, when the police raided it in the early morning, setting off a riot by 300 young men in which 13 were arrested and four police officers injured. It marked the beginning of the homosexual rights movement. Yesterday, Mr. Manford, a third-year student at the Benjamin N. Cardozo School of Law at Yeshiva University, walked shirtless up the middle of Fifth Avenue with his mother, Jeanne, and tens of thousands of other homosexual men and women, some of their parents and some of their friends.

The awards ceremonies of the Moscow open chess championship today followed the usual pattern of congratulatory speeches, inside jokes and handshakes until the winner, Boris Gulko, asked to speak. An expectant hush fell over the officials and participants gathered in the ornate main hall of the Central Chess Club. It was common knowledge that Mr. Gulko, an international grandmaster and the Soviet champion in 1977, had not played in a major tournament since he and his wife applied to go to Israel in December 1978. Speaking nervously and rapidly, Mr. Gulko declared that he had written an open letter to the Soviet Chess Federation insisting that it take action to permit the emigration of the wife and son of Viktor Korchnoi, the defector who is scheduled to make his second bid in the fall to wrest the world chess crown from Anatoly Karpov of the Soviet Union.

Seated comfortably in his downtown office, looking out over Governors Island, Brooklyn and the East River, A. Robert Towbin grimaced at the mention of the thriving market for new issues. ''There's a thing about new issues that has a ephemeral quality,'' said Mr. Towbin, senior partner at L.F. Rothschild, Unterberg, Towbin. ''But we're here for the long run. ''You don't look at Rothschild just for new issues -you look at us for creative investment ideas.''

Two steel cables on the Brooklyn Bridge snapped last evening, severely injuring a pedestrian and causing the bridge to be closed for more than three hours. After the accident, which did not involve any of the strands supporting the weight of the roadway, traffic backed up on the Manhattan and Brooklyn sides until engineers assessed the damage. Cars were permitted across again at about 9:15 P.M., but pedestrians will continue to be barred until the damaged walkway is repaired. Leon Mandel of Manhattan was walking across the bridge from Brooklyn when the accident occurred at 5:50 P.M., near one of the towers on the Manhattan end.

Italy's Christian Democrats lost the post of Prime Minister for the first time in 36 years today as Giovanni Spadolini, secretary of the small Republican Party, was sworn in at the head of a 27-member coalition by President Sandro Pertini. Mr. Spadolini, the 56-year-old leader of a party that won only three percent of the seats in Parliament in elections in 1979, ended a monthlong Government crisis provoked by a scandal over a secret Masonic lodge by putting together a coalition that lacks only the Communist Party and the neo-Fascist Social Movement among major parties. Mr. Spadolini said in an interview that this was ''the first secular Government in the history of the Republic,'' and said it was ''a historic event because it established for the first time the practice of rotation of the Prime Ministership between the secular and the Catholic forces in the country.'' Role for Communists Is Unlikely He added that it was unlikely that the Communists would enter the Government during the five-year term of Parliament that will last until 1984 unless national elections have to be called early.

A man wielding a knife slashed eight homeless men about the neck in a series of apparently unprovoked attacks from the Bowery to Pennsylvania Station Saturday night and early yesterday morning, the police said. All eight men, slashed while they were either asleep or intoxicated, were listed in stable condition yesterday. Seven remained in hospitals and one was released after treatment. The police believe that the attacker moved on foot over a two-hour period from the Bowery to Greenwich Village to lower Madison Avenue to Pennsylvania Station. Four of his victims were white, three were black and one was a Hispanic man.

In a skillful display of how to influence Congress, the savings and loan industry has produced a stunning first-round victory for its bill to create a new type of tax subsidy for savers and financial institutions. The Senate Finance Committee and the House Ways and Means Committee voted overwhelmingly to include the new tax subsidy in the 1981 tax relief bill. The finance panel's vote was 20 to 0; in the Ways and Means Committee the tally was 29 to 3. Yet, doubts about final committee approvals had persisted. One reason was that neither committee had held even one day of hearings on the proposal. A second was that, in the Ways and Means Committee, neither of the proposal's chief sponsors voted for it.

President Reagan's economic plan appears to be holding its own in the business community, despite the unexpected allure of an acrossthe-board reduction in corporate income taxes proposed by the Democrats on the House Ways and Means Committee. Even efforts last week by the Democratic leadership, including Ways and Means Committee Chairman Dan Rostenkowski and Speaker of the House Thomas P. O'Neill Jr., to persuade business to back their version of business tax relief do not appear to have won many converts. Big business has lined up solidly with the Reagan plan, which centers on depreciating plant and equipment. Representatives of small business, though more interested in the new proposal, did not seem to be fighting for it although they said the plan would probably benefit them.

Thirty-three years after it began its evolution into the largest university system in the world, the State University of New York is still searching for its place in American higher education. With 374,000 students and 21,000 faculty members spread across 64 campuses, the university has fulfilled its primary mission of offering a low-cost college education to virtually every qualified student in the state. Its teaching is highly regarded, and the pace of federally sponsored and other research is intensifying. Nevertheless, none of its units have the prestige of a University of California at Berkeley or the University of Michigan at Ann Arbor - with giant libraries and a wide range of scholars and researchers at the top of their fields. And unlike the nation's top state universities, the State University of New York has not become a magnet for high-quality students from other states.

''Why should people who live in Penn Yan be paying for the ZZ train?'' -Richard Roth, spokesman for the State Senate majority leader, Warren M. Anderson. (B3:5.)

OMAHA DUSK was settling over Rosenblatt Stadium here and the sinking sun lit the light towers in the outfield red. It was humid, but a wind had picked up - an ill wind, very ill, bringing the unmistakable odor from the sewage plant a half-mile away. Jim Buckner hardly noticed. He sat in the corner of the home team's dugout while most of the other Omaha Royals were on the field randomly warming up for the game against the Springfield Redbirds. Buckner slapped a gnat on the blue stirrup stocking of his uniform, and then discharged a stream of tobacco juice from under his furry red mustache. A reporter sat down beside him. ''Heard anything yet?'' Buckner asked. ''No,'' said the reporter. ''Just thought you might have a pipeline,'' said Buckner, with a little smile. This was last Tuesday night, possibly the last night of Buckner's last best chance in professional baseball. For 10 years Buckner, a left-handed outfielder, has bounced around the minor leagues, always with the dream to make the major leagues - and join his older brother, Bill, a first baseman-outfielder with the Chicago Cubs, and last season's National League batting champion. Bill Buckner has been a major leaguer for 12 seasons.