What was going on when I was born?

President Reagan sent a thank you letter today to 145 House Democrats who had voted in favor of increasing the American contribution to the International Monetary Fund, thus attempting to remove a major roadblock to final Congressional approval of the increase. The Democrats had demanded the letter from the President after the Republican Congressional Campaign Committee had attacked them for voting last August against an amendement to the quota increase bill. The amendment, sponsored by conservative Republicans but opposed by the White House, would bar I.M.F. loans to ''Communist dictatorships.'' With the letter out of the way, the Reagan Administration still has to meet another condition of the Democrats for their continued support of the bill, which would increase by $8.4 billion the American contribution to the monetary fund. As a quid pro quo, the Democrats want the Administration to increase Government subsidies for housing for the poor.

News Analysis WASHINGTON, Oct. 24 - The devastating bomb blast in Lebanon has left President Reagan a man under siege, tested politically and personally more severely than at any other time in his tenure. It is clear that the past 72 hours have have taken their toll on the President. He looked exhausted, emotionally drained, even old for the first time in his Presidency when he stepped from his helicopter and reached for an umbrella in the pouring rain on the South Lawn of the White House Sunday morning. It was 8:30 A.M., six hours after he had been awakened with the first news of Marine Corps casualties. As he began to speak to reporters, he took his wife's hand seeming to need moral support. Her face showed an anguish that aides said was stirred not only by the bombing in Lebanon but also by the incident Saturday at the Augusta National Golf Club in Georgia where a gunman seized several hostages, demanding to speak to the President.

SAN FRANCISCO APROPOSAL to build a Ronald Reagan Presidential library at Stanford University in Palo Alto has prompted a campus debate. There are three parts to the proposed complex: the library and a Ronald Reagan museum, both of which would be managed by a Federal archivist at a cost of about $2 million a year to be paid by the Federal Government; and a Ronald Reagan institute on public affairs to be managed by the Hoover Institution on War, Revolution and Peace. In its present form, the proposal to locate the Reagan papers at the Hoover Institution is the product of a recently formed Hoover committee, though Mr. Reagan's longstanding links with the institution have apparently given rise to such suggestions for years. Some members of the Stanford faculty see the Hoover Institution, which was established on the campus in 1919 with a gift from Herbert Hoover of $50,000 and his papers up to that time, as a national center for conservative political activity. Earlier this year, faculty demands for change in the university-institution relationship led the Stanford trustees to create an oversight committee to consider ''matters of governance, appointments, sharing of scholarly resources and other matters of mutual interest'' between the university and the Hoover Institution.

A front-page map yesterday incorrectly located the United States Marine headquarters blown up in a terrorist attack in Beirut. The correct location is shown today in the diagram on page A12.

WHEN John Stapylton Habgood started studying and teaching science at Cambridge University more than three decades ago, he had what he considers his first religious experience - a realization that the kinetic theory of gases describes quite elegantly and accurately what the properties of a gas will be. ''It was one of the beautiful things that you are constantly finding in science,'' recalls Dr. Habgood. ''An experience of beauty, of order and of mysteries revealed.'' But gradually, as he earned his doctorate in physiology at Cambridge and became a lecturer in pharmacology, Dr. Habgood came to feel that something was missing in his scientific training. Science achieved its enormous practical successes, in his view, by narrowing its focus, dealing primarily with things that can be measured or weighed, and excluding human values as much as possible. ''In science, you deliberately cut out all the interesting human things,'' says Dr. Habgood, ''so we are left with this hard, meaningless, valueless universe and we recoil in shock if we think that's all there is.''

SALT LAKE CITY NEARLY a year after Dr. Barney B. Clark was rushed to the University of Utah Medical Center for an artificial heart implant, and seven months after his death, a moratorium is in effect on the implanting of the device in a second human. The anguish of seeing several sick applicants die while waiting for a chance to receive an artificial heart has led Dr. William C. DeVries, the surgeon who did the first implant, to stop taking further applications until the moratorium is lifted by the university's institutional review board. Even prisoners on death row and a healthy 60-year-old woman who wished to donate her body to help mankind are among those who have wanted to volunteer for the artificial heart experiment. They were rejected because the benefits would not have outweighed the risks, Dr. DeVries told a recent conference on the ethics of the artificial heart held at Alta, a nearby ski resort.

TUESDAY, OCTOBER 25, 1983 Companies G.M. reported its earnings surged to $737 million in the third quarter, nearly six times higher than in 1982. Analysts cited increasing big-car sales. A.M.C. lost $9.1 million. (Page D1.) Merrill Lynch's earnings fell 67 percent, reflecting slower securities trade; Phibro-Salomon had a 12.7 percent decline. (D1.)

Not long ago, an international crisis one day would raise the price of gold by $15 to $20 an ounce the next day as investors rushed to buy the precious metal as security against uncertainty. But at least for the last three years, gold prices have remained relatively stable when crises have hit the headlines. Yesterday, for example, the day after the tragic explosions in Beirut, the price of gold rose by just $3 on the London Metal Exchange and only $4.90 an ounce, to $398.30, on the Commodity Exchange in New York. Similarly, after the Soviet Union shot down a South Korean airliner in early September, gold prices hardly rose despite serious international tensions.

Most new companies are satisfied to begin life with a nest egg counted in thousands, or perhaps millions, of dollars. On Jan. 1, with the divestiture of the American Telephone and Telegraph Company, seven new companies will spring forth fully formed, each with nearly $20 billion in assets and $10 billion in revenue. Markedly smaller than the old A.T.& T., they will nonetheless rank as giants of American industry, bigger than Consolidated Edison, Pacific Gas and Electric, and bigger than virtually every other utility in the United States. Each will have as much assets as United States Steel and more revenues than Chrysler or Dow Chemical, and will be bigger than all but a handful of American companies. For the executives tapped to lead these companies, it is the stuff of which dreams are made. But their experiences could just as easily turn into nightmares.

A report in New York Day by Day yesterday on the thwarting of a battery theft from an automobile misidentified the car owner and the man who stopped the theft. They were Bob Moskowitz and Charles Coleman.

T. Boone Pickens Jr., chairman of the Mesa Petroleum Company, said yesterday that an investor group he heads now owns 10.8 percent of the Gulf Oil Corporation, adding that it ''cannot be assumed that the investors will be passive.'' Despite his prior silence on the reasons for buying Gulf stock, some Wall Street analysts said the statement appeared to pave the way for the Texas oilman to start a long-expected proxy fight with Gulf management for control of the big oil corporation. Others, however, said the statement left unclear how active Mr. Pickens would be in opposing Gulf. In a filing with the Securities and Exchange Commission, Mr. Pickens said that his group, which includes the Belzberg brothers of Canada and Wagner & Brown, a leading independent oil producer in Texas, had increased its holding in Gulf to 17.9 million shares - 10.8 percent - through market purchases last week.

Merrill Lynch & Company, suffering from the decline in securities trading and an increase in costs, yesterday reported that its third-quarter earnings plunged 67 percent from the same period last year Phibro-Salomon Inc., the big commodity and securities trading firm, reported a 12.7 percent drop in earnings. Most of the major brokerage firms are reporting lower earnings for the quarter. The decline in part reflects costs of extra personnel and equipment, added to accommodate the trading surge that began in the third quarter of 1982, only to dry up a year later. Merrill Lynch For Merrill Lynch, parent of the nation's largest brokerage firm, third- quarter earnings fell to $33.1 million, or 38 cents a share. from $100.3 million, or $1.23 a share, in 1982. Revenues were flat, at $1.31 billion.