What was going on when I was born?

Tucked away in the heart of this New Jersey city, the Prudential Insurance Company of America is somewhat removed from the competitive fervor of Wall Street. But geography has not daunted the Pru's expansion into financial services, and its desire to add new lines of business. Not content to be both the largest life insurer and the largest private money manager in the United States, the mutual company recently made a $385 million bid for the Bache Group, the fifth-largest retail brokerage firm in the country. For Prudential thinks Bache has the potential to be No.1. ''Acquiring Bache will be a very significant step in our strategic plan to offer a broad range of financial services,'' said Robert A. Beck, Prudential's 55-year-old, cigar-chomping chairman. ''From our standpoint, it is an extension of a program we have already been on.''

The Reagan Administration publicly took the position today that despite all the worrisome signs, a Soviet invasion of Poland is neither imminent or inevitable. Others with long experience of Moscow's policies expressed serious caution about the outlook. They see the Kremlin either aiming to install tougher leaders in Poland or pressing the present leaders into a crackdown against the independent labor union, Solidarity, and inclined to resort to force if the Polish Communist Party does not take tougher action. With Leonid I. Brezhnev now visiting Prague, several former high American officials are drawing parallels between the intensive Soviet pressure on Poland and the moves that Moscow made in 1968 as a prelude to the invasion of Czechoslovakia by Warsaw Pact powers. Then as now, there were menacing military maneuvers, high-level meetings and propaganda charges about ''counterrevolution'' and Western subversion.

SHOP for specials and redeem coupons: These are obvious methods of stretching grocery dollars. By applying a number of other commonsense strategies, the budget-conscious food shopper - and who isn't? - can further alleviate the pain at the supermarket checkout counter. It is hardly consoling to know that the percentage of the consumer dollar spent on food in the United States, less than 20 percent, is low compared with that in other countries. (For example, the average Latin American spends 64 percent of his income on food and does not eat as well.) But there is every indication that our food prices will continue to escalate while the budget is squeezed by rocketing costs of housing, energy and transportation. The little purple numbers and the unit prices are not going to shrink, so careful planning is essential. People who manage their grocery money well usually take the time to project their needs for the week, outlining menus and writing lists. Even if you live in Manhattan and market frequently, it's a good idea to plan from week to week.

ONCE most of us have filed our tax returns, we feel too poor and depressed to entertain. But take heart. If you've invited friends for dinner it is possible, even these days, to serve a delicious dinner to eight guests for less than $25. Mexican and Indian food is the inspiration for the two menus given on page C6. The food may be exotic but it is not expensive. The two cuisines rely heavily on spices and aromatics, chili peppers, coriander and mint leaves.

The New York City Taxi and Limousine Commission is expected today to impose a 50-cent surcharge for night and Sunday taxi rides in what it says is an effort to get more cabs on the city's streets. If approved as expected, the extra charge would go into effect by the end this month for an eight-month trial period. As proposed, the charge would be added to rides taken from 8 P.M. to 6 A.M. daily and all day Sunday. The surcharge is designed to encourage more taxi drivers to work during hours in which, according to commission studies, there is a scarcity of cabs.

New York City has spent about $285 million in the last three years under its program to take over tax-delinquent apartment buildings, rehabilitate them and restore them to the tax rolls, but it has sold only 200 of the more than 10,000 it has acquired. More important, nonprofit community groups and tenant associations, which the city hoped would buy many of the better occupied buildings, have bought only 16. The remainder were primarily vacant buildings sold at auctions or to private developers guaranteed Federal rent subsidies. The program, run by the Department of Housing Preservation and Development, is known as ''in rem,'' a name derived from the legal term for actions against property. Foreclosure is the only way the city can penalize the building owners because it has no legal right to recover the delinquent taxes through other assets the owners might have.

The New York Times/Edward Hausner Venturing out into the Polar Bear Moat yesterday at the Bronx Zoo, Russia stayed close to her cub, Snowflake, born last Nov. 23. In the rocky retreat of a herd of Sardinian wild sheep, a lamb nestled close to its mother. Mother was nowhere in sight at the Bird House, but John Wilhelm, a keeper, offered comforting words to a newly hatched tawny frog-mouth bird, which was quite at home sitting in a basket.

After the Arab oil embargo and the recession several years ago, AMF Inc. found itself with an amalgam of unprofitable leisure companies, a ballooning debt and a consumer less than eager for such corporate trademarks as Head skis, Harley-Davidson motorcycles and Hatteras yachts. After taking stock, the leisure and industrial technology company decided to start mixing more business with less pleasure. ''That period was a shocker that forced us to set new objectives for the corporation,'' said W. Thomas York, AMF's chairman and chief executive officer. ''We had to change a lot of what we were to get to where we wanted to be. Our strategy was to posture the corporation evenly across our leisure and industrial markets so that we could grow some in bad times and a lot in good times.''

Leonid I. Brezhnev, the Soviet leader, said today that he thought Polish Communists would be able to end the country's crisis by themselves. Eight hours later it was announced that the Soviet-bloc military exercises known Excerpts from speech, page A8. as Soyuz '81, which had lasted three weeks, arousing fears of an imminent Soviet invasion of Poland, had ended. All troops, including those who joined the maneuvers over the weekend, were rapidly returning to their bases, an official Soviet statement said.

Reaction to hijacking points up stability of Pakistani regime A2 Afghan rebels are said to win major victory A2 U.N. officials uncertain on peace- keeping role in Lebanon A3 Filipino voters give big margin to Marcos on charter revisions A4 Around the World A5 Iran closes largest opposition newspaper A6 3 East German leaders said to favor intervention in Poland A8 Excerpts from Brezhnev's ad- dress A9 Government/Politics Fight begins over Voting Rights Act extension A10 U.S. reports says households vic- timized by crime have declined A10 Puerto Rico considers compulsory licensing of journalists A13 Reagan support indicated on se- crecy for covert agents A14 Reports find business gifts to top Congress leaders increase A15 Democrats join offensive against Reagan economic program A18 Food stamp battle on Capitol is joined but is already half over A25 Florio announces candidacy for gubernatorial nomination B2 City shutting down unlicensed electronic arcades B3 Former prosecutor testifies about retainer at Margiotta trial B6 Energy No flooding damage found to Rec- tor No. 2 at Indian Point B2 General Around the Nation A11 Car identified in Halberstam mur- der trial A22 New York getting Miss Universe contest first time B2 Relative questions identity of a murder victim B4 East Side tree lover seeks exemp- tion on watering ban B4 The Living Section Food Supermarket strategies: How to save money C1 Dinner for eight for less than $25 C1 In a bitter price war, real wine bargains C1 The 60-Minute Gourmet C3 Making nonwheat bread before Passover C3 Wine Talk C16 Living Child-abuse parley deplores fund cuts C1 Metropolitan Diary C2 Kitchen Equipment C2 Best Buys C8 Discoveries C12 Personal Health C14 In Paris, fashion incursions from abroad C18 On the scent of what sells a per- fume C18 Health/Science Countdown near resumption on shuttle launching B7 Education/Welfare New Coleman study criticized by educators at capital seminar A12 City considers switching to a new public school reading test B3 Arts/Entertainment Federico Fellini's "City of Women" opens C21 International theater festival in Baltimore in June C23 James Taylor: After the turmoil and the wanderlust C24 "Modelmaker's Handbook" re- viewed C26 Houston Ballet at Brooklyn Acad- emy of Music C26 The Philadelphia Orchestra at Carnegie Hall C26 Obituaries Alfred Jensen, painter D23 Sports Leafs evoke a conditioned re- sponse from Islanders B8 Kings' Martin gets big test against Rangers B8 Mets' hopes for improvement hinge on pitching B9 Yanks say Nelson, 20, is right- hand man B9 Bucks beat 76ers, 109-99 B9 Red Smith on baseball's opening B11 Features/Notes About Washington: the session of the gun lobbyists A16 Notes on People B8 News Analysis Hedrick Smith examines Wash- ington view of Poland A1 John Darnton assesses prospects for Poland A1 Martin Tolchin on Democratic budget alternative A24 Editorials/Letters/Op-Ed Editorials A26 Back into the frying pan Running down the M.T.A. The worth of a Korean promise Crime control, cost control Letters A26 James Reston: Moscow's war of nerves A27 Russell Baker: the cactus subma- rine A27 Steve Olson: in Guatemala, under foot A27 Rozlyn L. Anderson and Patricia L. Irvin: save Legal Services A27

Senior aides to President Reagan, increasingly concerned that his hospital stay might rob his economic program of momentum in Congress, began a counterattack today against the alternative proposals put forward this week by the Democrats. Appearing late this afternoon at the White House, Treasury Secretary Donald T. Regan assailed the proposal by Democrats in the House Budget Committee, which calls for a $713.5 billion budget in the next fiscal year, as a ''well-intentioned but inadequate'' alternative to Mr. Reagan's program.

Abbie Hoffman, the counterculture leader of the 1960's who surrendered in 1980 after six years in hiding, was sentenced yesterday to up to three years in prison. Last January he pleaded guilty to selling $36,000 worth of cocaine to undercover policemen in 1973. After imposing the sentence in State Supreme Court, Acting Justice Brenda Soloff postponed its effective date to April 21, at the request of Mr. Hoffman's lawyer. Under state law, Mr. Hoffman must serve a year before becoming eligible for parole.