What was going on when I was born?

Gulf and Western Industries and Prentice-Hall Inc. announced jointly yesterday that they had agreed to merge, creating the nation's largest book publisher. The agreement followed an offer by Gulf and Western to increase its previously rejected $70- a-share offer by $1 a share. Already one of the biggest conglomerates in the country, Gulf and Western is a major book publishing company through its ownership of Simon & Schuster, currently the sixth-largest publishing house in the United States. Prentice-Hall, a publisher of textbooks and professional materials used by lawyers and accountants, is 11th in the nation.

MICHAEL BERGELSON admitted that he had no inventory, no sales force and no customers. But if he had $1.4 million, he was telling a recent gathering at the Harvard Business School Club in New York, his nascent company would have profits of $1.7 million on $16.5 million in sales in three years. Mr. Bergelson, a 46-year-old Russian emigre with a doctorate in computer science and an eye to the main chance, was making his pitch at the club's ''new venture workshop,'' a monthly, two-hour forum at which would-be entrepreneurs are invited to send up their trial balloons - usually to see them shot down by experts. The workshop's purpose is to give entrepreneurs such as Mr. Bergelson free professional advice, access to venture capital and a salutary dose of realism.

Acknowledging that issues of states' rights were involved, the Federal Deposit Insurance Corporation said today that it was moving to restrict banks from going into new lines of business under authority recently granted by some states. The proposed regulations, which would apply not only to federally chartered, or national, banks but to state-chartered banks also, would restrict the ability of banks to engage in real estate; insurance brokerage and underwriting, and travel services. A number of states, including New York, have recently authorized state- chartered banks to enter these lines of businesses. In June, for example, the New York State Assembly approved a bill that would allow state- chartered savings banks to invest in and control real estate development.

The New York City Transit Authority proposed sweeping changes in its $6.3 billion rebuilding plan yesterday, calling for more money to buy new buses and overhaul subway cars. The reshuffling of the five-year capital plan would affect almost every aspect of the city's aging transit system, from elevated track structures to shops and barns. Under the new plan, more money would also be spent to rebuild bus depots and the Staten Island subway system. In addition more funds would be set aside for such items as air-conditioning, chemical car washes to remove graffiti, and improvements in television monitoring systems and other security measures.

THE dark world of bats has long been hidden from humans, surrounded by myth, fear and ignorance. But scientists have recently begun to discover that the world's only flying mammal is a much more sophisticated and benign creature than previously believed. Because bats are nocturnal, live in secluded caves and roosts, and are so different from all other mammals, thorough studies have been difficult. But new research in both the laboratory and the field, using such esoteric technologies as infrared scanners, high-frequency telemetry, luminescent wing bands and computerized data bases, have shed light on many of the mysteries of bats. As a result, this often maligned creature, possessor of what may be the oddest physique and strangest assortment of grotesque faces of any of earth's animals, is beginning to gain the respect of scientists and nature lovers. These are some of the findings:

Reagan Administration officials said today that the World Court's ruling that it had jurisdiction to decide Nicaragua's lawsuit against the United States would force Washington to consider whether to boycott further proceedings. Officials following the case said the 15-to-1 decision seemed to portend that the Court might eventually uphold Nicaragua's contention that the United States violated international law by supporting military attacks against Nicaragua and order an end to such support. The chief White House spokesman, Larry Speakes, said, ''We are disappointed with the Court's decision.'' He added, referring to four Latin American nations' efforts to solve the region's disputes, that the ruling ''will be harmful to the Contadora negotiations and will, accordingly, hinder rather than help achieve peace in Central America.''

The oil industry has taken many of the environment's riches over the last 50 years, but on this curving wisp of sand in the Gulf of Mexico some of them are being given back. For more than three years a small group of Texaco employees and students and faculty from Louisiana State University have been planting seedlings and erecting fences to build up sand dunes against the tropical storms that pound shoreward from the gulf at regular intervals. Timbalier is a barrier island, and in the bay behind its nine-mile bowlike shape are protected a thousand small wooden oil wells that look like matchboxes from the air, and fragile wetlands along the Louisiana shore - breeding grounds for the largest commercial fishery in the United States. Without the barrier, the wells and wetlands would be destroyed by the storms. Instead, the island, barely a half-mile wide, has absorbed the shock and is gradually being eroded. So with quiet intensity, little publicity and no fanfare, the highly unusual partnership of oil company officials and ecologists has been waging its own war against nature.

The United States and Iraq announced today that they had agreed to restore formal diplomatic relations. The move, which underscored the improving ties of recent years between Washington and Baghdad, was initiated by the Iraqi Government to balance its longstanding relations with the Soviet Union, Iraqi officials said. Iraq and several other Arab nations severed relations with the United States in 1967 after Israel's victory over Egypt, Syria and Jordan. In 1972, the two countries each set up small ''interest sections'' in the other's capital, and contacts have increased since then.

The World Court ruled today that it had jurisdiction to hear a case brought by Nicaragua that is aimed at declaring the United States an aggressor country. The Court voted, 15 to 1, against United States arguments that it had no jurisdiction in the matter. It then unanimously rejected the United States argument that it should not decide the case even if it had jurisdiction. The Court also ruled that preliminary restraining orders it issued against the United States in May, at Nicaragua's request, should remain in force pending resolution of the case. These called on the United States to halt any attempts to blockade or mine Nicaraguan ports and to refrain from jeopardizing Nicaragua's political independence by any military or paramilitary activities.

''Uruguay knew poverty, but it never before knew misery. Now we face a problem of generalized misery.

WHEN school began in September, Public School 62 in the South Bronx had 463 pupils. In the next seven weeks, 201 more pupils were admitted and 88 left. If this school year is anything like the past, and it looks like it will be, P.S. 62 will experience a turnover rate of more than 70 percent by June. In many places it is taken for granted that a child will start and end his education in one elementary school, enjoying the instructional benefits of continuity and the security inherent in a familiar social setting. But for some youngsters, particularly in inner-city schools, several moves in the first few years of school are not uncommon. At a school like P.S. 62, which runs from kindergarten through the fourth grade, 80 percent of the pupils who complete the fourth grade began school elsewhere.

CBS Inc. said yesterday that it had agreed to acquire for $57 million various interests in four regional pay cable sports channels operated by the Sportschannel, which is jointly owned by the Washington Post Company and Cablevision's Rainbow Program Enterprises. CBS also said yesterday that, as part of the transaction, it had agreed to acquire from Rainbow Program Enterprises a 50 percent interest in the Rainbow Service Company, which produces a two-channel cable service consisting of Bravo, a performing arts and international films channel, and American Movie Classics, which shows pre-1970 American films. In addition, CBS will buy 50 percent of the Rainbow Programming Services Company, which markets and distributes the Sportschannel services as well as the Rainbow Service on a national basis. These agreements are subject to definitive agreements expected to be reached by the end of the year.