What was going on when I was born?

President Reagan's proposal to eliminate almost all Economic Development Administration financing over the next two years would cut deeply into more than 60 factory expansions, industrial parks, small-business loan funds, theater rehabilitations and other projects in depressed areas in New York, New Jersey and Connecticut. Since the freezing of applications to the E.D.A. for grants, loans and loan guarantees totaling $304 million nationwide was made known earlier in the week, corporation executives and local officials have been scrambling to get the freeze rescinded and to find alternative financing for their endangered projects. Congressional approval is needed to end the programs involved, which are authorized under existing law. But the Reagan Administration has frozen applications for the programs in anticipation of asking Congress to act.

Administration officials said today that recently acquired information indicates that the anti-Government insurgents in El Salvador are running low on ammunition because of an apparent decision by Nicaragua and Cuba to reduce their assistance. Although the officials said that the intelligence information was not conclusive, there was a growing belief within the Administration that the flow of arms to the left-wing rebels in El Salvador through Nicaragua had been drastically reduced in the last several weeks. The officials said also that there has been less activity and involvement by Cuba in helping the El Salvador rebels during the same period. U.S. Is Proceeding Cautiously The Reagan Administration has been cautious in handling the intelligence information. It does not want to undercut its own justification for increased military aid for El Salvador but it is also tempted to assert that its ''tough'' position exposing Sovietbloc assistance to the insurgents may have been decisive.

The Byrne administration today modified some bans on the outdoor use of water in the 372 communities that have been under either mandatory rationing or milder forms of water controls. However, rationing allocations and fines for excessive use were not changed. Under the changes announced today, residential, country club and municipal swimming pools may be filled and new shrubs, trees and sod may be watered for up to 90 days after being planted. The change in policy comes amid increasing concern about economic setbacks among nurseries, lawn-care concerns, sod growers and the golf course and swimming pool industries. These interests were known to be worried about possible business losses had the restrictions lasted into the spring, their busy season.

For the first time since it woke up to industrial design in the 1950's, the International Business Machines Corporation has engaged an Italian-based designer as its chief consultant. Similarly, Renault in France and Volkswagen in West Germany have called on Italian designers to develop a new look in automobiles. Sony, the Japanese electronics company, has engaged an Italian to create a prestige line of stereo equipment. The French housewares company Teraillon regularly looks across the border for Italian industrial designers.

Louise Priester used to key-punch insurance claims into a computer in the office of Blue Cross-Blue Shield of South Carolina. Now she does the same thing from a bedroom in her house in Columbia, S.C., using a terminal connected to the office's computer by telephone. Like Mrs. Priester, a small but growing number of workers are doing office work at home on small computers or terminals with typewriter keyboards. Corporations encourage the practice, to save commuting time for their employees and to recruit some workers, such as mothers of small children, who might not be able to hold conventional jobs. Working at home gives employees more flexibility in scheduling other activities. ''I can get up when I want to and work when I want to,'' said Mrs. Priester, adding that she can now take better care of her elderly mother.

The Commerce Department reported today that retail sales in February rose nine-tenths of 1 percent over January figures, the ninth straight monthly gain. The growth was viewed as an indication of strength in the national economy. February's seasonally adjusted sales total of $85.8 billion was about 10 percent above the figure for the same month a year earlier, very nearly the inflation rate for the last 12 months.

O.P.M. Leasing Services Inc., which is under investigation because of reports that it put together questionable computer leasing arrangements, filed for reorganization yesterday under the Chapter 11 provisions of the Bankruptcy Act. The Manhattan-based company, one of the nation's largest computer leasing companies, listed liabilities of $504 million and assets of $446 million in its petition for court protection from creditors while it reorganizes its affairs. The bankruptcy petition was filed before Bankruptcy Judge Burton R. Lefland in the United States District Court for the Southern District of New York. The United States Attorney's office in Manhattan said Tuesday that it was ''investigating allegations related to O.P.M.'' This was prompted by industry reports questioning the concern's ability to honor leases on computer equipment that involve financing from major banks and Wall Street investment houses.

In a suprise announcement less than 24 hours after an unexplained flurry of trading in stock of the St. Joe Minerals Corporation, Joseph E. Seagram & Sons said yesterday that it was offering $45 a share, totaling more than $2 billion in cash, for the nation's No.1 lead producer. The price, almost three times St. Joe's book value of $16.50 a share, brought immediate resistance from the company and widespread conjecture that other bidders would soon come forward to touch off a heated takeover battle. Wall Street analysts have been suggesting privately that many of the nation's biggest natural resource companies will eventually come under siege from major oil companies looking for diversification candidates. The Royal Dutch/Shell Group, which already shares major coal operations with St. Joe, was viewed as a possible contender against Seagram. The Newmont Mining Corporation owns 7.3 percent of St. Joe, but its attitude could not be immediately determined.

EVEN though teen-agers are using contraception more conscientiously, increasing numbers are becoming pregnant because more are sexually active. That was one of the primary findings of a report entitled ''Teenage Pregnancy: The Problem That Hasn't Gone Away,'' published yesterday by the Alan Guttmacher Institute. The report projected that 4 of every 10 girls aged 14 would become pregnant at least once during their teen-age years, 2 of 10 would give birth and more than 1 in 7 would have an abortion. The report, a compilation of recent research, was designed by the institute, a Planned Parenthood affiliate specializing in research and education, as a sequel to a 1976 study, ''11 Million Teenagers: What Can be Done About the Epidemic of Adolescent Pregnancies in the United States.'' Richard Lincoln, senior vice president of the institute and author of the report, said it was an amalgam of ''probably 100 studies, each of which involved thousands of teen-agers.''

New York has its first construction site that apologizes - and maybe it's about time. With detours and debris inconveniencing pedestrians during the mid-Manhattan building boom, the 40-floor office tower at 767 Third Avenue, at 48th Street, began a one-way conversation with passers-by yesterday, expressing regrets for the mess and recounting interesting facts about its construction. ''Hello! This is the building speaking,'' said the message from two overhead speakers in the temporary passageway around the site. The man who writes the building's material is Peter Lehrer of Lehrer/McGovern Inc., which is erecting it for the William Kaufman Organization. The voice was recorded by a professional actor.

For the first time in at least 15 years many colleges and universities have begun systematically reworking their liberal arts curriculums. Institutions from New York University to the University of Idaho are requiring that students take certain courses and are introducing new programs in ''general education.'' Stanford University, for example, has restored a set of ''Western Culture'' requirements after an 11-year lapse, and the faculty of Brooklyn College, after a three-year debate, has decided to require all students to take a basic core of the same 10 courses to give them a ''common educational experience.'' Harvard University attracted national attention two years ago with its new general education program, but other schools have adapted the movement to their own needs. 'Educated Person' Hard to Define College officials give numerous reasons for the widespread interest in structured curriculums, from a desire by faculties to reassert authority after the academic freedom students gained in the 1960's, to the need to overcome what Henry Rosovsky, a dean at Harvard, termed the ''breakdown of common discourse'' among educated men and women.

The Federal Communications Commission yesterday approved a change in accounting rules for the nation's telephone system that will increase costs to consumers over the next decade, while reducing the borrowing needs of the phone companies. Nationwide, the commission's 4-to-1 decision will permit the phone companies to seek an estimated $17.6 billion to $21.05 billion beyond what they would otherwise be allowed to seek over the next decade. The additional charge to the nation's millions of telephone customers works out to $122 to $137 for each telephone now in use.