What was going on when I was born?

After a marathon 20-hour session, Governor Kean and the New Jersey Legislature enacted a package of tax measures early today that eliminates the need for $150 million in budget cuts the Governor had scheduled to begin Saturday. The package includes a Republican-sponsored 1-cent increase in the state sales tax, to 6 percent, that will take effect Monday, and a Democratic-sponsored increase of 1 percentage point in the state income tax, to 3.5 percent, on annual incomes above $50,000. The income-tax increase will affect earnings in 1983. Governor Kean signed the bills in his office shortly before 8 A.M. after a night of frequent meetings with legislative leaders and his staff. Package Called a Compromise Mr. Kean said he had mixed feelings about the measures - a reluctance to impose increased taxes but a sense of relief that further budget cuts had been avoided.

In his first year in office, Secretary General Javier Perez de Cuellar says, his greatest achievement was his remarkably blunt account of the United Nations' impotence. ''It is this report that contains something necessary,'' he said in an interview. ''My contribution is that I had the courage to sign the report.'' The document, issued in September, was largely a record of failure with some modest proposals for curing the world body's paralysis. It described the many arenas where the United Nations was unable to avert war or bring peace, deplored the repeated defiance of the Security Council, urged the Council to move in on conflicts before they erupted and promised that Mr. Perez de Cuellar would also practice preventive diplomacy to head off potential disputes.

At least four powerful bombs exploded in lower Manhattan and downtown Brooklyn within 90 minutes last night and injured three police officers, the police said. The bombs went off at Police Headquarters and three Federal buildings. One police officer was critically injured by the explosion at headquarters and the other two were injured by the explosion at the Federal jail in lower Manhattan, according to Sgt. Ed Burns, a police spokesman. In addition, the sergeant said, a number of ''suspicious packages'' were found next to other city and Federal buildings - including City Hall - and were being checked by explosives experts.

A strike threatened against the Hudson, Harlem and New Haven commuter rail lines was averted last night when the five unions still without new contracts agreed to work and continue negotiations. Richard Ravitch, chairman of the Metropolitan Transportation Authority, announced shortly after 6 P.M. that there would be no interruption in service on the rail lines, which carry 180,000 riders a day. Mr. Ravitch said one of the unions, the United Transportation Union, which represents conductors, brakemen and ticket takers. had agreed to a one-month extension of the talks. The four other unions, he said, had agreed to keep talking. He said he was hopeful agreements would be reached with the five unions during the next month.

The Soviet Union issued a statement through Tass, the official press agency, today declaring that its troops will remain in Afghanistan until longstanding Soviet conditions for their withdrawal are met. The statement appeared to be intended to reassure the Soviet-backed Government of Afghanistan and to curb speculation in the West that the new Soviet leader, Yuri V. Andropov, might be preparing to accept a face-saving settlement to extract more than 100,000 Soviet troops from a seemingly intractable war. The statement, while not quite as authoritative as an official Government pronouncement, is regarded as a clear indication of Moscow's views. It reaffirmed the terms set out by the Afghan Government in May 1980 and August 1981, which have formed the Soviet position on the war. These are that Soviet troops will be withdrawn once ''foreign armed intervention,'' meaning Moslem guerrillas fighting with Western backing, is ended. In addition, the Afghan leaders have demanded ''dependable international guarantees'' against a resumption of the fighting.

All 16 newly elected governors who will take office in January face the prospect of having to recommend tax increases or reduction of services because of a shortage of revenue, according to a check of state capitals. In some states, the deficits projected for the end of the current fiscal year have increased since the election Nov. 2. And interviews with their governors and their aides disclosed that the bleak fiscal outlook was threatening the plans to create more jobs that they advocated in their campaigns. In virtually every state, the slack economy and how to deal with it is the prime issue. Most Are Democrats The newly elected governors were also reported likely to add to the deteriorating relations between the state executives and President Reagan, who wants to transfer some Federal programs to the states but without the sources of revenue the governors say they need.

Countless Poles spent the waning days of 1982 the way they have spent much of the year: standing in line. There were long, long lines for loaves of bread today, to last through another long holiday weekend. Lines for vodka for tonight's New Year celebrations. Lines for gasoline - some 50 cars at one station - to get all of the month's ration before the coupons expired. Lines at the Pewex stores, the ever-growing special chain set up by the Government where rare Western goodies like chocolate bars, Scotch and brandy are available so the authorities can obtain foreign currency. Lines everywhere. The lines are the most constant and visible sign of Poland's woes. This week thousands of people formed a huge, intricately curled line that looked like a mob outside the state apartment agency, many staying round the clock for several days. They were trying to register their children, some of them infants, because the average waiting time for an apartment is well over 16 years. Of course, this can be shortened to a couple of weeks if the apartment hunter knows someone who can tap into the corruption that helps make the system work.

Canada's Roman Catholic bishops have taken the unusual step of issuing a political statement criticizing the Government's economic policy. The bishops said in a New Year statement, ''The fact that some 1.5 million people (a post-Depression high) are jobless constitutes a serious moral as well as economic crisis in this country.''

During the last weeks of the year, shops in the capital and hotels in tourist resorts were packed as Mexicans went on a wild shopping spree that seemed to contradict the daily headlines about the country's severe financial crisis. But rather than reflecting an illusion that prosperity would somehow continue, it was more like a final fling before the extreme hardship that awaits Mexico in 1983. "Prices are going to go up and wages are not, so spend while you can," said a young secretary as she visited the huge Perisur shopping center. "Money will soon be worthless."

The Government of President Suharto, apparently concerned after 15 years in power that Indonesia's official ideology could be challenged, has decided to require even firmer loyalty to five broad political principles listed in the preamble of the Constitution. Since general elections were held last May for the 364 elected members of the 460-seat Parliament, the President and his fellow generals have made it increasingly plain that they think the principles are still insufficiently accepted. As a result, two special steps are expected to be taken in March by the People's Consultative Assembly, the 920-member body in which supreme power is officially said to be vested. The assembly, of which Parliament is a part, is expected to insist that the principles be made a more integral part of the Constitution and that all political groups be required to declare their loyalty to them.

Former Secretary of State Henry A. Kissinger said today that accounts of the attempted assassination of Pope John Paul II last year led ''almost to no other conclusion'' than that it was an operation by the Soviet secret police, the K.G.B. Mr. Kissinger also said he had been told by Richard Helms, the former director of Central Intelligence, that the assassination attempt ''had all the earmarks'' of a K.G.B. operation. Mr. Kissinger gave his assessment in a television interview on the Cable News Network.

Scattered rioting and arson by Moslem mobs were reported continuing today in the southern Indian city of Trivandrum. Troops were sent in after three people burned to death and rioters attacked the police on Thursday.