What was going on when I was born?

As it moves from gawky adolescence to mature middle age, the international lending community is encountering some of its roughest going. For one thing, lending to countries, which has been one of the banks' favorite kinds of international business, has become far more uncertain after the problems in Poland, Rumania and now Argentina. Perhaps more important, the margins between the interest rates charged on international loans and the rates that must be paid on deposits have remained stubbornly narrow and, despite widespread predictions to the contrary, have shown only the faintest signs of improving. ''Nobody actively involved in the market can really be happy with the existing level of profitability,'' said M.C. Deverell, divisional general manager at Barclays Bank International. ''And yet, paradoxically, the plain fact is that we would have been talking or thinking in exactly the same vein at almost any time in the last decade.''

The United States and 10 European countries agreed yesterday to establish a new fare structure for North Atlantic routes that allows airlines more freedom in raising or lowering plane fares. The multilateral agreement, initialed in Washington by representatives of the 11 countries, will be formally signed later. It guarantees governmental approval of fare changes within certain agreed-upon zones, effective July 1. ''The agreement puts into the marketplace a much more competitive structure with not nearly as much government involvement,'' said Darrell M. Trent, Deputy Secretary of Transportation, who headed the American delegation at the talks.

An article April 22 about hearings in Washington on videotaping incorrect- ly described the testimony of the actor Charlton Heston. He said he supported a special royalty fee on the manufac- turers of home videotape recorders.

''The world should understand that the people of El Salvador are not cannon fodder for any appetite, for any dictator or for any cold war.'' - Alvaro Alfredo Magana Borja, the provisional President of El Salvador. (A10:1.)

If Harrods is an institution, it is often said here, then Liberty is a monument. But while that description of this city's other large department store may befit its splendid mock Tudor facade and high-priced gentility, it is not always the best way for a retailer to sell goods. Tourists ''just come in here as though it was the Tower of London,'' David Pike remarked ruefully upon his appointment last year as chairman of Liberty & Company. ''They don't buy.''

For many Japanese living in New York, it was a chance to go home again. Looking at the rows of cherry trees in the Brooklyn Botanic Garden and listening to the music of the stringed koto, Eiko Sakashita from Fort Lee, N.J., sighed to her husband, ''Don't you think it's like Japan?'' But as her husband pointed out, the Botanic Garden's first recreation of Japan's cherry festival was also a chance for Japanese to share one of their favorite customs and some of their proudest artistic traditions with their American neighbors. Although the cherry trees have bloomed in the garden for over 40 years, this is the first organized cherry blossom festival.

Long after most insurgents have forgotten their legal and political battles with the Democratic organization in the city, a Democrat who was removed from the primary ballot last September is pursuing a potentially far-reaching damage suit in Federal Court in Brooklyn. The insurgent, Aaron Weiss, a self-described idealist who tried to challenge the Democratic nomination of City Councilman at Large Steven Orlow, contends that his constitutional right to run was violated by a ''conspiracy'' of public and party officials whose time and efforts were subsidized by city and state taxpayers. The 23 defendants include Stanley Fink, the Assembly Speaker; the city's Board of Elections commissioners and the top officials of the Queens Democratic organization headed by Donald R. Manes, the county leader and Borough President. The suit makes an issue of a longstanding political tradition in this city - the interlocking connections between public and party officials affiliated with the regular organization.

International An Argentine cruiser was torpedoed and severely damaged by a British submarine in the South Atlantic, the British Defense Ministry reported. The ministry said the cruiser General Belgrano had been a significant threat to Britain's fleet maintaining the air and sea blockade around the Falklands. The General Belgrano is Argentina's only cruiser. It was commissioned by the United States in 1939 and sold to Argentina in 1951. It carries a crew of about 1,000. (Page A1, Col. 6.) Argentina denied the British report that one of its cruisers had been torpedoed and said that it was ''a lie'' and ''psychological warfare.'' Western diplomats in Buenos Aires could not immediately confirm the statement by the British Defense Ministry. They said that the General Belgrano, a former American cruiser, was in poor mechanical condition and that they thought it was being withheld from combat. (A1:4-5.)

More than 100 new General Motors buses are sitting idle in New York City bus depots because of a dispute between the Transit Authority and General Motors over the operation of the vehicles' rear exit doors. The authority says that it is afraid to use the new buses because of problems that developed with an earlier order of General Motors buses; G.M. says that it is correcting the problem. ''We have withheld acceptance until we are satisfied with the fix on the door on the new buses as well as on the ones that we have in service,'' John D. Simpson, president of the Transit Authority, said in an interview yesterday. G.M. Says Buses Are Safe Gene al Motors, which has had mechanics in New York to check the operation of the buses now in service, says the new vehicles are safe and ready for use.

SAN FRANCISCO ASK Neil Allen to list the characteristics of a young pitcher capable of moving from the starting rotation to the bullpen and then learning to relish the job, and - with an impish giggle - he describes himself. ''Dizzy,'' said the Mets' 24-year-old reliever who already has six saves this season after winning or preserving 54 of the team's 108 victories in 1980 and 1981. ''A kid who talks a lot and is funny, who gets along with everyone. Not a complete idiot, but he'd have to have a sense of humor. If he takes everything seriously day in and day out, his mind would be shot by September.'' Ask George Bamberger the same question about Allen and he casts his mind back through a distinguished career as pitching coach of the Orioles and manager of the Brewers and comes up with virtually the same answer.

New Jersey's motor vehicle system is a marketplace of illegal payoffs from drivers who want their records altered and their suspended licenses returned, according to a former director of the State Division of Motor Vehicles. The director, Joan H. Wiskowski, who resigned in March after Governor Kean took office, had started a program designed to crack down on corruption and reduce the paperwork that makes it possible. She said in a series of interviews that while progress had been made, payoffs ranging from $25 to $350 were still common, sometimes changing hands inside the bustling division headquarters here on Montgomery Street. ''A lot of it is just people freelancing on the inside,'' Mrs. Wiskowski said, ''but what troubles us is that there are people - 'street people' - who seem to have the ability to steer the motorists with problems to the right people inside, for a fee. ''The overwhelming majority of division employees are honest, but there are people who are still operating,'' she said. ''And they are doing it even after some employees have been arrested.''

Industrial nations face another year of stagnant economic growth and higher unemployment because of the continuing high interest rates in the United States, the Organization for Economic Cooperation and Development warned its 24 member countries. At a meeting of top economic policy planners here that ended on Friday, the organization's secretariat, which monitors the performance of the industrial economies, said that it had revised downward its earlier growth forecasts as a result of the persistent tight monetary situation in the United States. The organization reported that it now expected economic growth to average only three-tenths of 1 percent during 1982, down from last December's prediction of 1.25 percent and a recorded growth rate of 1.25 percent by the industrialized nations in 1981.