What was going on when I was born?

A report in New York Day by Day on Nov. 8 about the mourning period for Terence Cardinal Cooke incorrectly accounted for the four red hats suspended from the ceiling of St. Patrick's Cathedral. Three belonged to Cardinal Cooke's predecessors; the fourth belonged to no one but represented the fourth Cardinal, Francis J. Spellman.

Martin S. Feldstein, the chairman of the President's Council of Economic Advisers, today stepped up his campaign to shrink the Federal budget deficits. His office issued several tables of figures that seemed to support the argument for tax increases. That argument has not made headway with the Administration or Congress. The figures show that domestic spending, except for Social Security and Medicare, is falling substantially after adjustment for inflation, and they seem to imply that a further shrinkage in this part of the budget is not likely. They also show that a steady rise in interest payments on the Federal debt is eating up these savings.

GEOLOGISTS now believe that one of the great master rivers of world history once flowed west from the eastern portion of the United States and was responsible for much of the land and stream formation as far west as the Mississippi valley. Its deep gorges and broad valleys, as well as remnants of its many tributaries, now lie hidden under glacial deposits covering the region south of the Great Lakes. Not until recently has the existence of such a river - probably formed more than two million years ago and almost certainly never seen by human eyes - finally become accepted. Yet early explorers of the Ohio River drainage basin did begin to note early on that there was something very mysterious about its topography.

North Korea is stepping up its arms sales and military training in other countries, according to diplomats and other experts on the region. Some experts say that North Korea's need to generate cash may be a reason not only for the new arms sales but also for heightened smuggling by the Pyongyang Government's embassies abroad. The diplomats and experts also say that a power struggle may be under way in the Pyongyang hierarchy that could partly explain the involvement of North Korea in recent violence abroad. On Oct. 9 a powerful bomb exploded in Rangoon, Burma, killing 17 South Koreans, including some of Seoul's highest-ranking officials. Burma blamed North Korea, severing relations, and even allies such as China have expressed dismay.

''I have indicated today, as I have stated time and time again both before and after these hearings, that I will stand behind police officers when they are right and condemn them when they are wrong.

The McDonnell Douglas Corporation, one of the nation's leading aircraft makers, said yesterday that it had reached an agreement in principle to buy Tymshare Inc., the operator of one of the nation's largest data transmission networks, for $378 million in cash. The merger would enable McDonnell Douglas, already deeply committed to computers to meet its aircraft needs, to combine its vast computer services with a sophisticated data communications network that now links 42 countries. In a joint announcement after 10 days of negotiations, John F. McDonnell, president of McDonnell Douglas, and Thomas J. O'Rourke, chairman of Tymshare, said that stockholders would receive $31 a share in cash for Tymshare's 12.2 million shares outstanding but that the aircraft company reserved the right to pay $32 a share in stock. In a move that would automatically give McDonnell Douglas a profit if it is outbid, terms of the agreement provide that Tymshare grant the company ''promptly'' an option to buy 2.25 million shares of new Tymshare stock at $31 each, or $69.75 million.

GUILT, long blamed by comedians as well as therapists for countless cases of emotional misery and psychological crippling, is being increasingly viewed as a valuable and uniquely human feeling that is essential to social order, moral behavior and ultimately the survival of the species. ''Contrary to the tenets of pop psychology, guilt is hardly a 'useless' emotion,'' said Dr. Willard Gaylin, a New York psychotherapist who is the author of ''Feelings: Our Vital Signs.'' For example, one best-selling psychologist has called guilt the most useless of our feelings and by far the greatest waste of emotional energy. But Dr. Gaylin rejects that assertion. ''Guilt, the sense of anguish that we have fallen short of our own standards, is the guardian of our goodness,'' Dr. Gaylin said. ''It is necessary to the development of conscience in children and to the avoidance of antisocial behavior.''

In a series of management changes intended to blunt the widespread criticism of its handling of the nuclear accident at Three Mile Island, the General Public Utilities Corporation yesterday announced the resignation of R. C. Arnold, the president of its nuclear power subsidiary, and the expansion of the subsidiary's board to include three outside directors. G.P.U., a holding company for three public utilities that own the Three Mile Island plant, announced the changes at a hearing before the Nuclear Regulatory Commission in Washington. In part, the company said, the changes are being made in response to ''open issues concerning management competence and integrity'' at the site of the 1979 accident. New Permit Sought The company also said it hoped the changes would help persuade the Federal agency to authorize the start- up of Unit 1 at the Three Mile Island site, a reactor that lies adjacent to the one that was severely damaged in the 1979 accident. Unit 1, which was taken out of service temporarily when the accident occurred, has never been put back into operation.

During his first year in office, Governor Cuomo has angered or disappointed a number of the groups and individuals who helped elect him, and the Governor has embarked on what his aides describe as an effort to restore good relations. ''We want to re-establish and maintain communication,'' said the Governor's secretary, Michael J. Del Giudice. ''Where misunderstandings existed, we want to get them cleared up.''

U.S. military cooperation with Israel is being increased, according to Reagan Administration officials. They said the President had agreed to lift a suspension of delivery of American cluster-bomb artillery shells and had agreed to ease Israel's financial problems by not requiring it to repay any American military aid in the next fiscal year. (Page A1, Column 6.) Washington-Peking ties were stressed by the White House, which took pains to declare that recent Congressional support given to the Chinese Nationalist Government in Taiwan was contrary to Administration policy of recognizing the Communist regime in Peking as the sole legitimate Government of China. (A1:5.)

The space shuttle Columbia carried a European-built research laboratory into orbit today to begin nine days of scientific tests and observations by the crew of six men, including a West German physicist. The Columbia was launched on its journey on schedule at 11 A.M. Eastern standard time after what officials at the Kennedy Space Center described as an almost perfect countdown, free of any serious problems. Within hours the Columbia had settled into a 155-mile-high orbit and the astronauts and scientists were going about their tasks in the 17-ton, 23-foot- long Spacelab that occupies the shuttle's cargo bay. The laboratory, built in West Germany for the European Space Agency at a cost of $1 billion, is outfitted with instruments to conduct more than 70 experiments in astronomy, atmospheric physics, materials processing, earth observations and physiology. Spacelab Unharmed by Liftoff Initial reports indicated that the Spacelab and its complex apparatus had survived the jolt of liftoff and appeared to be in good condition. Communications between the laboratory and ground stations, by a satellite link, were checked out and found to be loud and clear. Television images of the crew's early work in the Spacelab were transmitted by the Tracking and Data Relay Satellite.

President Reagan has approved steps to increase American military cooperation with Israel, including resumption of delivery of American-made cluster-bomb artillery shells, Administration officials said today. The officials said Mr. Reagan also agreed to ease Israel's financial problems by not requiring it to repay any American military aid for the next fiscal year. However, the total amount of that aid would be reduced. Mr. Reagan made these decisions before starting two days of talks today with Prime Minister Yitzhak Shamir, Defense Minister Moshe Arens and other high-ranking Israelis. The Israelis are also seeing other senior American officials.