What was going on when I was born?

American, Brazilian and West German scientists announced jointly today that a skeleton recently exhumed from a graveyard near here was unquestionably that of Dr. Josef Mengele. A separate report by American experts concluded that the bones were those of the long-sought Nazi death-camp doctor ''within a reasonable scientific certainty.'' Under questioning, the Americans said they had ''absolutely no doubt'' of their findings and ruled out any possibility of a hoax. U.S. Accepts Conclusions In Washington, Attorney General Edwin Meese 3d said the Justice Department accepted the group's conclusion, while in Los Angeles, officials of the Simon Wiesenthal Center for Holocaust Studies said they were ''99 percent'' satisfied that the skeleton was Dr. Menegle's. [Page 8.] There was no immediate response from the Israeli authorities, who had said last month that they would await the forensic experts' reports before drawing a conclusion on whether or not the remains were those of Dr. Mengele.

The New York City Council voted yesterday to widen restrictions on food peddlers in the congested streets of midtown Manhattan and to extend similar limits to crowded sections of lower Manhattan, Brooklyn and Queens. Mayor Koch said he would sign the measure, which is aimed at reducing the crush of pushcarts selling hot dogs, ice cream, knishes, pretzels and other foods during daylight hours on some of the world's busiest sidewalks and street corners. Merchants, theater organizations and other business interests had backed the bill, contending that congestion was becoming overwhelming in some areas. Representatives of thousands of street vendors had opposed the bill, saying it would hurt peddlers and their customers. Vendors who violate the regulations face having their merchandise confiscated by the police.

As the Beirut hostage crisis entered its eighth day, Prime Minister Shimon Peres of Israel and Secretary of State George P. Shultz agreed on the importance of not yielding to the demands of the hijackers holding 40 Americans hostage in Beirut, the State Department said. Their conversation, by telephone, was said to be the first high-level Israeli-American contact since the Athens-to-Rome T.W.A. Flight 847 was hijacked by Lebanese Shiite gunmen last Friday, with 153 passengers and crew aboard. It appeared to be part of an effort to reduce the strain in relations that has developed since the hijacking. With no visible progress in achieving the release of the hostages, Administration officials were cautioning that the crisis could continue indefinitely if Nabih Berri, the Amal Shiite leader, who has become the central intermediary, refuses to free the Americans unconditionally. Reagan Sees Limit to Restraint In Dallas, President Reagan said the United States would continue to show restraint in the aftermath of recent terrorist acts, but warned that ''no one'' should doubt America's resolve to counter such attacks. [Page 4.] The Administration has been seeking support from many foreign governments, particularly those with possible influence on Mr. Berri. A major effort has been concentrated on persuading President Hafez al-Assad of Syria, who is currently in the Soviet Union, to support the unconditional release of the Americans.

Hundreds of Moslem demonstrators chanting ''Death to America' and ''Death to Reagan'' held a mass rally at the international airport here today, where they cheered the hijackers of the T.W.A. airliner. The march was organized by the pro-Iranian Shiite group called the Party of God, whose members were believed to have commandeered the Boeing 727 last Friday. In some ways, it was a scene reminiscent of the Iranian hostage crisis that ended in 1981. Many of the demonstrators carried huge posters of Iran's fundamentalist Shiite leader, Ayatollah Ruhollah Khomeini.

The National Collegiate Athletic Association today overwhelmingly approved the strongest sanctions it has ever enacted against colleges and coaches who violate rules governing recruiting, amateurism, academic standards and ethics. The sanctions, approved by N.C.A.A. member institutions at a special convention here, will take effect Sept. 1. They include suspension for an athletic team for as long as two seasons if it is found guilty of major infractions twice in a five-year period. Facing what some convention delegates have described as an ''integrity crisis'' in collegiate athletic programs, the representatives also agreed to suspend or dismiss any coach involved in major violations and to suspend the college's right to recruit athletes in the sport. A repeat offender would also be prohibited from awarding new athletic scholarships in the sport for two years.

A young man shot and killed his mother and himself today on the seventh floor of the State Department, about 100 feet from the office of Secretary of State George P. Shultz, officials reported. The District of Columbia police said the man, 20-year-old Edward Steven Doster, killed his mother, Carole Doster, 44, just after noon. The two lived at different addresses in Alexandria, Va. Mrs. Doster was a secretary in the office of Edward J. Derwinski, a former Republican Congressman from Illinois who is the State Department counselor. A senior State Department official said Mr. Doster had a history of mental illness. The State Department said tonight that Mrs. Doster, who had filed an assault complaint against her son with the Alexandria police, had asked the department to revoke his permit to enter the building. The request was still being processed.

This is the story of the hijacking of Trans World Airlines Flight 847 up to this point, as told by those who have been freed so far. Those who spoke withheld some details, and some said they were doing so because Federal authorities had warned them that the remaining hostages could be jeopardized by their remarks. As Trans World Airlines Flight 847 waited to take off from Athens International Airport on the hot, windless morning of Friday, June 14, few passengers gave any thought to a minor commotion that had taken place at the terminal just before boarding. A young, slender, Arabic-speaking man named Ali Atwa had gotten into an argument with T.W.A. ticket agents because they refused to let him board. The jet, they told him, was already full with 145 passengers.

Israel finds itself in a quandary over how to respond in the Beirut hostage crisis, and Israeli experts on terrorism say they believe it is an indirect result of the Government's decision last month to trade 1,150 prisoners, most of them Palestinians, for 3 Israeli prisoners of war. The experts say that by giving in to the demands of a Palestinian guerrilla leader, Ahmed Jabril, last month -a move widely viewed here as a blunder - Israel helped to create the atmosphere in which the Beirut hijacking took place. Now, the experts argue, Israel is trying to compensate for this by refusing to concede to the hijackers' demands for the release of 766 detainees unless the United States formally appeals to the Israeli Government to, in effect, ''cave in'' to the demands. Friction Between Allies This has created a great deal of strain between Jerusalem and Washingtion, and officials here acknowledge that coordination between the two Governments has been inconsistent. The result, said Zeev Schiff, the military editor of the daily newspaper Haaretz, is that the hijackers have already won a major victory: Israel and America, instead of fighting the hijackers jointly, are at odds with each other.

An American who brought his light airplane to Moscow on an officially approved ''friendship flight'' spent his three days here locked in a hotel because he arrived without a visa. But the flier, Millard Harmon, 59 years old, a retired college administrator from Delmar, N.Y., was all smiles as he passed out ceremonial gifts to his hosts before he left today.

As Prince Norodom Sihanouk tells it, his friend came to him one day and said, ''You've lost a country, the least we can do is to build you a house.'' The friend was Kim Il Sung, one of the most forbidding figures in the Communist world, and the house he built for the Prince on a wooded hillside outside the North Korean capital was fit for a king. The Prince, King of Cambodia as a teen-ager, and later Prime Minister and constitutional head of state, tells visitors that the 40-room mansion in this austere workers' state is the grandest residence he has ever had. ''I call it my palace,'' he says, breaking into the nervous laughter that punctuates much of his conversation. On the face of it, the politics of this region has produced few odder couples than the Prince, 63 years old, and Mr. Kim, his 72-year-old benefactor.

Scores of arrests were reported today, the day after five bombs exploded in this Himalayan city of temples, killing 7 people and wounding 24. The kingdom's official press agency said the police had found nearly 100 unexploded bombs. The attack was the first major terrorist act in Nepal. One of the explosions Thursday blew down the lobby roof of the luxury Annapurna Hotel, and another tore the door off the National Assembly chamber, killing a legislator. Two bombs exploded at gates of the royal palace.

A moderate earthquake shook the Aegean island of Euboea early today, but no damage or casualties were reported. The Athens Seismological Institute said the earthquake occurred at 3:15 A.M. local time and measured 4.4 on the Richter scale, signifying that it could have caused moderate damage in a crowded area. The Richter scale is a gauge of the energy released by an earthquake as measured by the ground motion recorded on a seismograph.