What was going on when I was born?

The 13 OPEC oil ministers who gathered here to seek an accord on lowering oil prices postponed their first full meeting until Tuesday - and perhaps later - after Iran insisted it would never agree to a cut in OPEC's official prices. Instead of the expected meeting, the day and evening were spent in a series of negotiations among small groups within the Organization of Petroleum Exporting Countries. The setback tempered the optimism that had prevailed among the eight ministers who had called for a full meeting. This group, led by Saudi Arabia and Venezuela, has held informal talks over the past 10 days; by last Thursday, they seemed to be making headway.

International The Pope condemned violence and the persecution of Guatemalan Indians. John Paul II, who arrived in Guatemala from El Salvador, repeatedly stressed the themes of human rights and the sanctity of human life, issues of high sensitivity in Guatemala, where the Government last week rejected a plea from the Vatican and executed six men whom a secret military tribunal had found guilty of subversive acts. (Page A1, Column 1.) A meeting of 99 third world nations opened in New Delhi and heard Prime Minister Indira Gandhi stress conciliation on political issues and appeal for immediate debt relief and more aid for poor countries. The Indian leader said that such aid should be followed by a world conference that would seek to overhaul the international monetary and financial system. (A3:1-3.)

Japanese companies seeking new employees typically have one goal in mind: hiring the graduates of leading national universities. Masaya Nakamura, president of Namco Ltd., however, takes an entirely different approach. In colorful magazine advertisements, Namco, a producer of video games, solicits reformed juvenile delinquents and C students. ''For game designers,'' Mr. Nakamura explained, ''the knowledge acquired in school is not so helpful. I want people who think in unusual ways, whose curiosity runs away with them, fun-loving renegades.''

Dillon, Read & Company, the Wall Street investment banking house, said yesterday that its managing directors had agreed to buy a sufficient number of Dillon, Read shares from the Bechtel family of San Francisco to give the banking house's management control of the firm. Neither company would disclose the number of shares changing hands or the terms of the transaction. In June 1981, the Bechtels, through their Sequoia Ventures Inc. investment company, bought the bulk of the shares of the 152-year-old private banking house from C. Douglas Dillon, the former Treasury Secretary, and his family as an investment. The number of shares was not disclosed, but Dillon, Read said it was considerably more than 50 percent of the 30,000 outstanding.

New York State won 8 of the top 10 awards tonight in the annual Westinghouse Talent Search. A 16-year-old student from the Bronx High School of Science, Paul Ning of Washington Heights, won the first prize, for a project in advanced number theory. One of the judges said that Mr. Ning's project, for which he received a $12,000 prize, showed ''a very sophisticated understanding of number theory not commonly found in one so young.'' The Westinghouse prizes are considered among the most prestigious in the nation for aspiring scientists.

Nearly 90,000 commuters joined car pools and crowded onto buses, subways and clogged highways yesterday as a trainmen's strike shut down New York City's principal rail arteries from the north and east. The strike against Metro-North - the railroad's first in 10 years - halted all 527 trains on the Hudson, Harlem and New Haven lines and brought to 160,000 the number of metropolitan-area commuters afflicted by rail strikes. The 70,000 riders of N.J. Transit, New Jersey's main commuter rail system, which was shut down by a strike of the same trainmen's union last Tuesday, continued yesterday to resort to car pools and buses, as they had last week. Shoulder-to-Shoulder Crowds With both strikes under way, some traffic and transit officials had predicted chaos. But despite rain, fog, delays, long queues, unfamiliar routes and a bit of grumbling, the bulk of Metro-North's riders made a relatively smooth transition to alternative transportation.

WHEN President Reagan announced several months ago that he was postponing United States efforts to negotiate a complete ban on nuclear testing, the underlying arguments for that decision began a debate among scientists that has grown more heated with each passing week. The Administration decision, aides said, was motivated partly by its belief that the United States lacked the ability to determine whether the Soviet Union would be able to cheat by secretly detonating nuclear tests. But does it lack the ability? Some scientists feel that the capacity for adequate ''verification'' as it relates to a nuclear ban - as well as to two key treaties that limit atomic testing - is available from current technology. They contend that the Administration is using a technical rationale for a political decision - namely, that testing is in the nation's security interests.

Attorney General William French Smith today issued new guidelines making it somewhat easier for Federal agents to investigate groups that try to ''achieve political or social change'' through the use of violence. The stated purpose of the new guidelines is to give the Federal Bureau of Investigation greater latitude in investigations, but without eroding protections for lawful, peaceful political dissent. The rules are the first comprehensive revision of the standards for domestic security investigations that were issued seven years ago, in the Ford Administration, by Attorney General Edward H. Levi. The Levi guidelines were issued in the wake of disclosures that the F.B.I. had engaged in widespread spying on Americans in civil rights, antiwar, feminist, Socialist and Communist organizations, as well as the Ku Klux Klan and some right-wing groups in the 1960's and 70's.

Orphans of the storm and of the strike, 90,000 commuters greeted the grayest of Mondays yesterday. They left their beds before dawn to try to reach their jobs before lunch, employing an impromptu armada of buses and vans, limousines and station wagons, car pools and subways. For even the veteran of fare increases, wheel inspections, power shortages and standing on those long rides home - in short, the average passenger - yesterday's strike on Metro-North demanded new reservoirs of resolve. Coffee helped, too.

Gary Gross said that at a time when image was everything - when people wear their clothing tags on the outside and insist on French water that bubbles with sophistication - he should not be surprised that officials in this suburb have passed an ordinance forbidding him and other tradesmen to park vehicles with commercial license plates in their driveways overnight. But he is. ''The Mayor wants it to look like only accountants and stockbrokers live here,'' Mr. Gross, a heating and air-conditioning repairman, said. ''We feel like second-class citizens.''

THE guide high in the mountains bordering Rwanda and Zaire motions to the members of his small group to be still. Rare and endangered mountain gorillas, which are capable of crushing a human skull with a single bite of their large jaws or of easily breaking a neck with arms that span seven feet, have been sighted in a clearing in the thick jungle. The guide emits a kind of long, rolling belch. He is, in deference, using apespeak, and he is signaling peaceful intent. The group has trekked through mud slides, bamboo thickets and clumps of wild nettle and rough grass to make a passing acquaintance with a distant relative on the evolutionary time scale. The paths before they petered out have been steep and slick, the nettles aggressive and the heat has been enveloping. Now the moment has come.

The price of Chock Full o'Nuts stock rose yesterday amid speculation on Wall Street that a new battle would soon develop for control of the big coffee producer and restaurant chain. The renewed fight for the company, following the death yesterday of William Black, the 80-year-old founder, chairman and chief executive of the company, would come from a group of investors headed by Jerry Finkelstein, a 66-year-old financier whose holdings include The New York Law Journal and The National Law Journal. The Finkelstein group, which owns or controls an estimated 17 or 18 percent of Chock Full o'Nuts stock, lost a proxy fight last December to unseat the management team headed by Mr. Black, whose group owns about 35 percent of the stock and holds a majority on the 15-member board.