What was going on when I was born?

Mayor Koch, extolling the virtues of New York City with his own irrepressible brand of salesmanship, lectured students and entertained crowds here today. On the second day of an official four-day visit as part of a sister-city program, the Mayor met with Prime Minister Felipe Gonzalez, was honored by the City of Madrid and repeatedly answered questions from Spaniards about President Reagan's victory in last week's election. Mr. Koch has also witnessed the training of bullfighters, eaten prodigious amounts of the Spanish specialty angulas - tiny eels with garlic - and, in celebration of ''New York Week in Madrid,'' attended an outdoor demonstration of break dancing.

President Reagan's top economic and political advisers agree that he should seek deep domestic spending cuts, despite the likelihood that Congress will reject them, key Administration officials said today. Administration officials said the urgency of the budget situation had been heightened by reports that projections of the Federal deficit had grown because of the slowdown of the economy in recent months. Officials said the latest projections showed the deficit would be at least $190 billion in the current fiscal year and in each of the next four years if there is no action by Congress. These estimates are nearly $20 billion higher than those made by the Administration in August.

THE arrival of Veterans Day seems to trigger the onset or return of mental problems among a growing number of Vietnam veterans, the legacy of unresolved emotional difficulties that stem from hostilities that ended more than a dozen years ago, according to doctors who have been monitoring such cases. Nightmares, vivid flashbacks of painful memories, acute panic attacks, chronic startle reactions and a proclivity toward violent aggressiveness are some of the difficulties reported by thousands of veterans each month. And in the view of several experts, rather than diminishing with time as might be expected, cases serious enough to warrant professional help have yet to peak, and can be expected to rise for another year or two. They say this is because the veterans, who averaged 19.2 years of age when they served, are now reaching the age when other midlife pressures exacerbate their troubling war memories. Although comparative figures on mental stress from past wars are not available, the severity of the fighting in Vietnam, the youth of the combatants and the failure to acknowledge and deal with the possibility that many soldiers were vulnerable to mental stress combined to intensify the problem, the experts said.

FROM now until Dec. 21, residents of the northern latitudes will experience a continuous decrease in a substance that has recently been shown to counter depression, increase alertness, inhibit sleepiness and perhaps stimulate sexual reproduction. That substance is sunlight, worshiped by people since earliest times for reasons that science is just now beginning to understand and extend. Findings described this month to the first wide- ranging scientific conference on the biological and medical effects of light indicate that both real and artificial light can have health benefits far beyond those imagined by science even as recently as four years ago. Researchers at the meeting described pilot studies in people using light to treat seasonal and other types of depression, jet lag and a form of leukemia. These were in addition to already established treatments for psoriasis, jaundice in newborn infants and bone loss resulting from vitamin D deficiency. And they outlined such future possibilities as light therapy to treat autoimmune system diseases, to counter rejection of transplanted organs and to target drug attacks on cancers, as well as using drugs to simulate the effects of natural light on moods and body rhythms.

The three fugitives and their wives and 12 small children lived in Ohio for more than two years, their lives on the lam shielded by carefully stitched subterfuge. Everybody was fooled - teachers, landlords, neighbors. The patterns of deception matched. The men - sought in the murder of a New Jersey state trooper, an attempted murder or bank robberies - were seen around the houses only on weekends. The wives kept to their homes, staying away from schools, shunning chitchat and avoiding neighbors and social commitments except for occasional car pooling.

OVER the course of a decade chemists have learned to blend, beat and bake different kinds of ceramic compounds into materials that are stronger than steel, hard as diamonds, and tough enough to take the heat of a blast furnace. The science of ceramics has reached a turning point. ''The market is set to explode,'' said Dr. Roger R. Wills, director of ceramics research at Battelle Memorial Institute. Even today, industries as diverse as energy, electronics, transportation, aerospace and medicine are using advanced ceramics in ways no one could have imagined a decade ago. Moreover, the field has generated anxiety in Washington as some scientists worry over whether the United States, with its history of considerable achievements, is doing enough. Last week the National Research Council warned that Japan was surging toward world leadership in high- tech ceramics, evoking fears of yet another technology race.

Martin Rapaport talks about free trade and the First Amendment, but finally it comes down to simple geography. ''Forty-Seventh Street has to recognize that it's in America,'' he says. On the Street, however, many diamond dealers have a different perspective. ''The man is out of line, he doesn't follow the rules,'' says William Goldberg, one of the most prominent dealers. What is at issue is the Rapaport Diamond Report, a weekly list of prices that dealers on the Street - the block between Fifth and Sixth Avenues through which pass 80 percent of the diamonds sold in this country - are asking for polished stones. Even its opponents admit that the report, which Mr. Rapaport has published since 1978, has become the industry's bible.

A major American news organization detailed the purported misconduct of a prominent military leader in a far-off, unpopular war. The official said his reputation had been blackened by the charge, which he denied. So he filed a multimillion-dollar libel suit against the media giant in Federal court in Manhattan. It all sounds like Gen. William C. Westmoreland's case against CBS. But it describes another explosive legal battle, scheduled to begin this morning six floors higher up in the Federal courthouse: the libel suit of the former Israeli Defense Minister, Ariel Sharon, against Time magazine. Charges 'Blood Libel'Mr. Sharon, the architect of Israel's war in Lebanon and now Minister of Industry and Commerce, has charged that he was libeled in 1983 by a Time article suggesting that he condoned, if not directly encouraged, the September 1982 massacre by Christian Phalangists of Palestinians in the Sabra and Shatila refugee camps near Beirut.

TUESDAY, NOVEMBER 13, 1984 Companies Two new offers emerged for Pabst, the nation's sixth-largest brewer, each valued at $63 million. One bidder, Paul Kalmanovitz, said he had a firm agreement, but Pabst said it was still considering the other offer, from Heileman Brewing. (Page D1.) Chrysler plans to spend $10 billion in the next five years on new products and facilities, $500 million more than it had forecast. But officials said the company was unlikely to reopen plants closed during the company's financial crisis. (D1.)

TUESDAY, NOVEMBER 13, 1984 International Israeli officials expressed optimism that a formula could be worked out with Lebanon to allow troop withdrawal talks to resume tomorrow. But there was no sign from Beirut that the Lebanese would accept anything short of their original demand - that Israel free a group of Shiite Moslem militia leaders arrested in south Lebanon. (Page A1, Cols. 4-5.) Renewal of American-Iraqi ties will be announced Monday, according to Reagan Administration officials. Baghdad severed relations with Washington in 1967. (A14:3-4.)

A table of election results in Metropolitan Report on Thursday misstated the vote for Aurelia Greene, who was returned to the State Assembly from the 76th District in the Bronx. She received 15,650 votes.

to an effort to cut Federal income tax rates, while weeding out some deductions and exemptions that reduce taxes. Who would win and who would lose? As the Treasury drafts a plan, two proposals in Congress offer a preview of a ''modified flat tax.'' Page A24.