What was going on when I was born?

After two years of intense legal, scientific and political maneuvering to liberate 3,600 acres of valuable real estate occupied by squadrons of shy blue butterflies, Sherman Eubanks seems more amused than angry. ''Eight hundred thousand dollars,'' he says, his voice somewhere between rueful and chuckling. ''We have spent $800,000 chasing butterflies.'' Mr. Eubanks is president of a land development company called Visitacion Associates, formed nine years ago to develop sites for thousands of housing units, what would be a small city, on San Bruno Mountain just south of San Francisco.

President Hosni Mubarak promised today that even after Egypt regains all of Sinai from Israel on April 25, ''we will continue to build bridges of understanding and friendship with the Israeli people.'' ''This policy is irreversible,'' Mr. Mubarak said in a speech to the National Press Club on the last of his three days in Washington. ''It is the trend of the future. In fact, the completion of Israeli withdrawal from Sinai will open the door for more interaction between Egyptians and Israelis. It signals the removal of another psychological barrier on the road to full peace.''

The General Assembly adopted a sweeping resolution today that urges nations to isolate Israel for annexing the Golan Heights. Eighty-six nations from the third world and the Soviet bloc voted for the document and 21 nations, including nearly every industrialized country, voted against it. There were 34 abstentions, largely from Latin America and the Caribbean, although a few were from Africa, and 16 nations were not present. The resolution, which is a recommendation, not a command, declares that the Golan Heights annexation was ''an act of aggression'' and calls on all member nations ''to cease forthwith, individually and collectively, all dealings with Israel in order totally to isolate it in all fields.''

Laker Airways, the brash upstart company that dramatically transformed air travel across the Atlantic with its nofrills fares, declared bankruptcy today and halted all flights. For Sir Freddie Laker, the colorful entrepreneur who built a clientele of budget-minded backpackers and pensioners, the final defeat in what he called ''the battle against the big guys'' came over a question of company debt. The company, which began its discount Skytrain service in 1978, had been urgently trying for months to reschedule more than $350 million in loans that had been floated in the past year or two to buy new planes for expanded service. Laker had planned to use the planes for new routes, including some to Europe. But delays in starting the new routes, the recession and stiff competition over the North Atlantic, where competitors had cut their rates, restricted Laker's revenue growth. The airline was unable to meet its debt payments, and when the end came, Laker still owed more than $300 million.

New York City's convention center is a hole in the ground just off the Hudson River, a thicket of pillars amid mud puddles and construction rubble, but already, its operators say, the files in its sales offices are bulging with acceptances. ''We're 79 percent booked through 1986,'' said Jerry Lowery, the executive director of the Convention Center Operating Corporation.. Between the projected opening in mid-1984 and the end of 1986, he said, 199 shows of various sorts, shapes and sizes are scheduled. Soon Mr. Lowery will be able to shift his personal emphasis from salesmanship to building a staff. His agency has a current paid staff of eight and occupies borrowed offices at Battery Park City; as executive director, he is paid $110,000 a year.

The arrest of a senior Soviet military attache last weekend came after the Federal Bureau of Investigation arranged for an informer to pass to him what the Russian was led to believe was a sensitive document, a high-ranking Government official said today. The official said F.B.I. agents were on the scene when the informer handed the document to the diplomat in a shopping center in suburban Washington. The attache, Maj. Gen. Vasily I. Chitov, was detained by bureau agents and later declared persona non grata and expelled. Although General Chitov's arrest and expulsion became known Thursday, it was not until today that it was disclosed that the F.B.I. used an informer to trap the Soviet diplomat.

Reagan Administration officials today projected a deficit of $91.5 billion for the next fiscal year, a sharp increas e in military expenditures and deep cuts in social programs. The projections were given to members of Congress in a preview of th e Administration's budget. The budget for the fiscal year 1983, which begins Oct. 1, projects total spending of $757.6 billion and revenue of $666.1 billion. David A. Stockman, director of the Office of Management and Budget, told a news conference that ''the whole thing will be difficult'' compared with the Administration's sweeping political successes in cutting this year's budget. 'Facing Severe Deficits' ''We're facing severe deficits,'' Mr. Stockman acknowledged. ''It's going to be a matter of weighing the choices available.'' The Congressional Budget Office said today that prospects for a modest recovery later this year and next year were threatened by growing deficits and the tight monetary policy of the Federal Reserve Board. The nonpartisan research office's three-volume economic forecast also predicted continued high unemployment. (Page 8.)

Five Americans are being held in Iranian prisons in addition to a naturalized United States citizen jailed nearly two years ago, the State Department said today. The department confirmed the identity of two male prisoners as Terry Graham and Erwin David Rabhan.

Chancellor Helmut Schmidt hopes that today's victory in a confidence vote in Parliament will bring an appearance of stability to his Government, but the expression of support carries very few guarantees with it. After a series of events in which he has been undercut by the left wing of his party, by dismal showings in public opinion polls and by worsening employment statistics, the vote may serve as a tonic and arguing point for the Chancellor inside West Germany and abroad. But none of the Chancellor's supporters who have been busy trying to describe the confidence motion in a positive sense seem to feel safe or bold enough to promise a new surge of energy or unity from the 13-year-old coalition of Social Democrats and Free Democrats. The political realities that led to the confidence motion suggest continuing difficulties, and the necessity of the vote itself reflects a collection of embarrassments that will be hard to expunge.

PEKING JOURNAL IMPLIES PURGE OF PARTY MAY BE IN THE OFFING PEKING, Feb. 5 (AP) - An article in the latest issue of the official journal Red Flag suggests that an extensive purge of party ranks may be imminent. The article, citing what it called ''impurities'' in the 39 million-member Communist Party, was signed by Zhang Yun, deputy secretary of the Central Discipline Inspection Commission. It is believed that the targets of such a mass ouster are the same officials who rose to power during Mao Zedong's Cultural Revolution of 1966-76, a period of civil strife when the proper political loyalties counted far more heavily than any professional skill.

The United States and West Germany are divided over what course to follow next week when some 20 foreign ministers attend the Madrid Conference on Security and Cooperation in Europe. Western representatives, including Secretary of State Alexander M. Haig Jr., plan to criticize the military crackdown in Poland. Toughening its position since the Madrid meeting recessed on Dec. 18, five days after martial law was declared in Poland, the United States now believes that the conference should adjourn after the full-dress sessions next week. The Americans argue that the Polish situation makes it inappropriate to continue the talks here aimed at strengthening the Helsinki accords of 1975, which were the high-water mark of detente.

Britain imposed economic and diplomatic sanctions on Poland and the Soviet Union today to demonstrate displeasure with the imposition of martial law in Poland. The British Government said the movements of Polish and Soviet diplomats here would be restricted, and some officially guaranteed credits to Poland would be ''placed in abeyance.'' The Government said no new credits would be issued, and the question of rescheduling Poland's 1982 debt would, ''for the time being, be held in suspense.'' It said exchanges with Soviet citizens under technical cooperation agreements would also be reduced.