What was going on when I was born?

Industrial companies have reported a pronounced turnaround in February, with new orders, production levels and other economic indicators up sharply, according to the National Association of Purchasing Management. In a monthly survey based on interviews with the purchasing managers at 250 companies, the association said it found that the level of production at those companies was increasing more rapidly than at any other time in the 30 years that the survey has been taken. New orders for these companies' products also increased sharply, the association said. In addition, it reported that the speed of deliveries had slowed for the first time since May 1981. This is regarded as an early reflection of expanding economic activity because slow deliveries usually mean large backlogs of orders.

The Economy Industrial output last month rose at the fastest rate in 30 years, purchasing managers said. They reported that new orders also climbed, while the pace of deliveries slowed for the first time since May 1981, indicating a growing backlog of orders. (Page D1.)

Argentina eliminated the United States in the first round of the Davis Cup tennis tournament today when Guillermo Vilas stunned John McEnroe in three straight sets. Leading by 4-2 in the first set, McEnroe, in an extraordinary lapse, dropped 15 straight games. The 6-4, 6-0, 6-1 victory gave Argentina an unbeatable 3-1 lead in the three-of-five series against the defending champions. In a truncated match that was meaningless, Gene Mayer defeated Alejandro Ganzabal, 6-3, 3-6, 10-8, making the final score 3-2.

Had a visitor from Mars suddenly been deposited on Third Avenue and 51st Street on a recent drizzly Friday evening, he might have thought that the natives were waiting to hail their leader. Dozens of anxious looking men and women lined the avenue, one hand raised high in what appeared to be a form of salute. In fact, the New York natives were only trying to hail a cab. For most, the effort proved frustrating. As in other parts of Manhattan on that and similar evenings during what is commonly, if ironically, known as the rush hour, almost every yellow car on the road either already carried a passenger or displayed an illuminated sign reading ''On Radio Call.'' How to relieve the shortage of cabs at the times when they are most needed is just one of a host of problems that have come to be associated with the taxi industry in New York City. Passengers and experts on the industry complain, too, of cabs that are sometimes unsafe or unclean, and of some drivers who are rude, who refuse fares on the basis of race or physical handicap, who do not know their way around the city, who will not go to certain destinations or who speak little English.

Of all the pain and problems the recession has produced, none may be as severe or long-lasting as the damage done to the health of people who, having lost their medical insurance along with their jobs, are not getting the medical care they need. ''This tragic byproduct of unemployment may, in the not so long run, cost the nation as much in damaged and lost lives as the unemployment itself,'' Douglas A. Fraser, president of the United Automobile Workers, said last month. Although no one has determined the exact extent of the problem, which is difficult to measure, experts in the field across the country point to troubling developments that include the following: - Eleven million people lost their health insurance in 1982 alone, the Congressional Budget Office reports, with most retaining too many assets to qualify for help under welfare programs. The Health Security Action Council, a labor-backed group, estimates that at least 25 million people now lack health insurance because of unemployment. - In Michigan, with the highest unemployment rate in the country, the infant death rate rose 3 percent from 1980 to 1981, to 13.2 deaths per 1,000 live births from 12.8 in 1980. In the same period the national rate declined by 6.4 percent, to 11.6 per 1,000. Experts say loss of health insurance and of proper prenatal and maternity care is one of the factors in the rise in Michigan.

During a recent fur sale at Bloomingdale's, three saleswomen were seated comfortably on chairs, chatting, as a lone browser wandered in. Alexander's fur department was similarly deserted. And Revillon, Saks Fifth Avenue's French-based fur department, was also empty on a recent Saturday afternoon - despite markdowns of up to 70 percent from retail prices. ''Volume is definitely down,'' said Maurice de la Valette, Revillon's vice president.

Reagan Administration officials privately expressed relief today at the outcome of the West German election, with its decisive endorsement of the Government of Chancellor Helmut Kohl. There was collective satisfaction not only because Mr. Kohl had explicitly supported President Reagan's policy on strategic arms, including the so-called zero option for eliminating medium-range nuclear weapons in Europe, but also because of the strength of his mandate. 'There Was a Certain Concern' ''The West is saved,'' an Administration official responsible for West German affairs said with a chuckle, adding that he was only half-joking. ''While all the poll projections for Kohl looked confident enough during the last 10 days,'' he said, ''underneath there was a certain concern here.''

It was an event of distinction as one of today's five inaugural games in the United States Football League, but distinctions were not expressed on the field here as the New Jersey Generals lost, 20-15, to the Los Angeles Express. Herschel Walker, the heralded halfback of the Generals, did not play a significant role in his first professional game. And there were six turnovers, five going against the losing team. The Express, an efficient outfit that gave away only one harmless turnover, almost lost by allowing the Generals a last chance at victory.

An article Friday on increased college costs gave an incorrect total for tuition, room and board at Cornell University in 1983-84. It is $12,300.

Construction cost overruns for New York City's Exposition and Convention Center will reach at least $16.8 million, according to center officials. Despite the added costs, however, the West Side project will remain under the $375 million budget ceiling set by the State Legislature, according to George Schoepfer, the head of the state agency building the center, the New York Convention Center Development Corporation. Mr. Schoepfer said the $16.8 million would be obtained from a contingency fund that had been included in the original budget and from interest earned on money raised through bond sales but not immediately spent.

LARRY LEMBO was minding his own business. For the previous several hours, he had been at work on a basketball court at Alumni Hall in Jamaica, Queens, making decisions and blowing his whistle during a Big East Conference game between St. John's and Syracuse. More than 30 minutes after the game, his whistle put away and his black-and-white striped shirt replaced by a coat and tie, the referee walked in a corridor beneath the stands. He was met by Jim Boeheim, the Syracuse coach, who was there to inject some constructive criticism in the form of a request. ''When are you going to give me a call?'' Boeheim said again and again, loud enough to be heard down a corridor and around the corner. ''You don't want me to give you a call, do you?'' Lembo said, patiently. ''What about the one at the end of the first half?'' Boeheim said, far less patiently. ''You missed it. You admitted it.'' ''That was one,'' Lembo said. ''Give me one,'' Boeheim pleaded. His voice was so loud that people on the other side of Alumni Hall later wanted to know what the commotion was about.

''Honest politics is persuasive politics.'' Chancellor Helmut Kohl. (A1:6.)