What was going on when I was born?

Last December, the United States General Services Administration decided it was time to get serious about Dial-a-Joke. By its reckoning, employees of various Government agencies at 26 Federal Plaza in Manhattan were spending so much time ringing up Dial-a-Joke - and 25 other New York Telephone Company Dial-It Services lines that offer everything from recorded horoscopes to betting results - that it was adding up to $3,000 a month to the Federal Government's local phone bill. The unauthorized, so-called ''junk calls'' appear to be proliferating, at private concerns as well as at government agencies, and employers concerned about trimming operating budgets say their phone bills are being driven up as a result. The telephone company says it received 299 million calls on its various Dial-It lines during l980, an increase of 34 million over l979. In l979, the last year for which revenue figures are available, the company earned $18 million from such calls.

Libya agreed today to receive the prisoners to be released by Pakistan at the demand of three hijackers who are holding more than 100 passengers and crew members aboard a Pakistani airliner here. The hijackers said yesterday that they would free their hostages after they had received notification that 55 prisoners held in Pakistani jails had arrived in Libya. The hijackers also asked to be flown to Libya, and this demand was accepted as well. A Pakistani diplomat at the airport told reporters early this evening that 49 prisoners who had been held in four different provinces in Pakistan were being gathered in Karachi and would be leaving Pakistani airspace ''in the direction of Libya.'' (A plane carrying the prisoners left Karachi for Syria Saturday, Reuters reported from Karachi.)

With his bride-to-be looking on, Prince Charles of Britain was thrown from his horse yesterday in an amateur steeplechase race at Sandown Park.

After an angry political wrangle, the board of the Metropolitan Transportation Authority voted 8 to 6 yesterday to pave the way for a probable July 1 fare increase. Board members shouted at each other across a conference table before they reached their decision. And, bowing to demands from Conrail constituencies for greater attention to their plight, the board also established a separate division to begin planning for a change in the commuter line's management. A board member from Rockland County, John McAlevey, called the move the first step toward an M.T.A. takeover of Conrail's passenger service in the region.

A Reagan Administration proposal could sharply reduce the amount of Federal education grants for about 1.5 million college students in the next school year. If approved by Congress, the proposal would defer, at least for this year, the use of a cost-of-living factor for adjusting the socalled ''discretionary family income'' that is the basis for determining the amount of a grant. ''Discretionary family income'' is the amount of money a family has left after paying essential living costs, such as housing, food and medical expenses. The amount of a Federal grant to a needy college student is based on how much discretionary income the family has available to contribute to that student's education.

Antonia Huntley dropped out of Fashion Industries High School in 1977 after spending two years in the ninth grade. She liked her courses in cutting patterns for men's clothing, she said, but somehow she could not keep up with her academic subjects. ''How could I do the work if I didn't understand what I was reading?'' she asked, more plaintive than angry. She lowered her head and added that she read on a fifth-grade level and that her knowledge of mathematics stopped short of fractions. ''I was just sitting there getting dumber and dumber, so I left,'' she said. By dropping out in what school officials say is the typical way, Miss Huntley joined about 37,000 other young people - most similarly lacking in basic skills - who drop out of New York City schools each year.

The Reagan Administration disclosed today that 15 of the American military advisers being sent to El Salvador are members of the Army's Special Forces who would train troops in counterinsurgency. Senators said that they had been assured at a briefing today that there were no plans to increase the number of advisers being sent to El Salvador beyond the 54 already announced, including the members of the Special Forces, who are known as Green Berets. Senior officials also said at a Senate briefing that the Administration, acting to help El Salvador economically, would request an additional $60 million for assistance in this fiscal year, according to Senate sources. The Administration plans to seek $80 million to $100 million in economic aid for El Salvador in the next fiscal year. This is roughly $100 million less than the aid requested by President Jose Napoleon Duarte. Officials stressed, however, that the economic aid was three times greater than the military help.

The Reagan Administration has succeeded in focusing world attention on El Salvador, but its monthlong campaign has also produced some negative side effects not to Washington's liking. Many key members of Congress and foreign governments that were only dimly aware of El Salvador's problems before are now openly concerned about the possibility of ''another Vietnam,'' even though the Administration insists such a comparison is unfounded. When Secretary of State Alexander M. Haig Jr. sent officials to Europe and Latin America last month to explain the Administration policy and ordered an information blitz on Congress and the press, his purpose was to expose what he said was Soviet-bloc support for the leftist insurgents in El Salvador and to gain sympathy for future United States countermoves. But as a senior Haig aide told reporters yesterday, Mr. Haig ''perhaps opened the jar and he didn't, perhaps, realize how many genies were in it.''

Tall, dark and handsome, dressed in a tuxedo, a brandy glass warming in his palm, he stood in the woodpaneled billiards room of an elegant mansion, exuding all the urbanity of a wealthy Latin diplomat in a Hollywood movie. Playing this role in a television spot for Bacardi rum, John Gavin has become widely known in Mexico in the last four years. Few Mexicans remember him from such films as ''Psycho'' and ''Tammy Tell Me True''; his image here is that of an actor supplementing his income as an elegant liquor salesman. But now, to the dismay of some Mexican officials and to the considerable amusement of local television viewers, word has reached here that Mr. Gavin is likely to be cast in real life as the next United States ambassador to Mexico.

Ahwaz, the capital of oilproducing Khuzistan Province, has become a virtual ghost town at night because of Tuesday's Iraqi missile attack, witnesses said today. Residents reached by telephone today said that thousands of people had fled Ahwaz since the attack and that the city was virtually abandoned every night for fear of a fresh bombardment. ''Many of the people hurry out of the city as soon as their work is finished,'' one resident said. ''Most of the population now consists of men. Women and children have been sent to safer places.''

The Greek Government said today that recent earthquakes had caused $2 million in damage to its antiquities and added that the figure was expected to rise.

Secretary of State Alexander M. Haig Jr. said today that ''outstanding differences'' between the Soviet Union and the United States ''have brought the state of world peace to a rather precarious level.'' Mr. Haig said he expected to meet soon with Ambassador Anatoly F. Dobrynin to begin a process that could lead to a meeting between President Reagan and Leonid I. Brezhnev, the Soviet leader.