What was going on when I was born?

Shooting of the Pope Pope John Paul II was shot and seriously wounded as he was standing in an open car moving slowly among more than 10,000 worshipers in St. Peter's Square. His accused attacker was identified as an escaped Turkish murderer who had threatened the Pontiff's life in the name of Islam. The Pope, who was struck in the abdomen, right arm and left hand, underwent 5 hours and 25 minutes of abdominal surgery. A hospital bulletin said he was in ''guarded'' condition, but the director of surgery expressed confidence that ''the Pontiff will recover soon.'' (Page A1, Col. 6.) The most serious damage was done to the Pope's intestines. Three sections of the bowel, or intestines, were removed in surgery, which was termed successful. A second operation will be required to reconnect portions of the bowel that were severed in a surgical procedure. Recovery is often complete, provided no complications develop. (A1:6.)

Home builders here, suffering from their longest and most severe postwar slump, have ripped a page from the auto industry's marketing manual and are offering home buyers a $2,000 rebate when they buy a new house. The idea has generated a lot of interest among builders across the nation and some are hailing it as a bold step that could generate more demand for new houses and relieve the battered builders of unwanted inventories. ''I think it's a great idea, especially if it shakes some people off the fence,'' said William Cheseroni, director of marketing for the National Association of Home Builders in Washington. ''There's lot of pent-up demand. People are afraid that they'll buy now and interest rates will go down. But they just keep going up.''

GRACIE MANSION, the official residence of the Mayor of New York, is an exquisitely sited house with a spectacular view of the East River. A wide veranda graciously circles the white farmhouse structure. Inside, the generously proportioned rooms are not so much appointed as furnished with antiques, some of museum quality, most not. The current resident, although reluctant to make too many changes, is nevertheless more than willing to reconsider the furnishings of the house. And Mayor Koch says that the planned renovation of Gracie Mansion won't cost his constituents anything and won't make him change his relaxed way of living.

From the day that Karol Cardinal Wojtyla stepped confidently onto the balcony of St. Peter's Basilica as the newly elected Pope John Paul II, he has boldly challenged the church and the world. Striving to make Christianity a renewed force, he has taken his message from St. Peter's Square around the globe, traveling widely with little apparent regard for his personal safety. The ''Popemobile,'' an open vehicle such as the one he was riding in when he was shot yesterday, has become a symbol of his mobility. Before his weekly audiences in the square, he stands in the vehicle as it winds through the crowds. The act is a byproduct of his instinctive showmanship and his irrepressible desire to bring the church to the people.

The Federal Trade Commission today officially ended its five-year antitrust investigation of auto manufacturing in America, one of the nation's largest and most concentrated industries. The termination, hailed by the car makers, had been expected since the commission's decision two months ago to withdraw subpoenas it had issued in its industrywide investigation. The reason given for both actions was that substantial economic changes have taken place in the industry since the investigation was begun in August 1976.

It is not yet built, and a lot of things can happen between now and 1987, when it is due to be completed. But if Battery Park City is built according to the plans just announced by the State Urban Development Corporation and the developers Olympia & York, it will be the finest grouping of skyscrapers since Rockefeller Center. The design, by the architect Cesar Pelli, calls for four major towers on the landfill site just west of the World Trade Center. There will also be plazas, a ''winter garden'' or galleria topped by a glass vault and two nine-story octagonal towers to serve as a gateway from Liberty Street. The $1 billion project is promising on two levels. First, it is impressive as urban design - the grouping of the towers and the open space is not only a handsome and civilized urban ensemble in itself, but also a dramatic counterpoint to that impossible neighbor, the World Trade Center. But more exciting still is the actual architecture: The four towers are probably the most successful attempt to give life to the skyscraper form in the last generation.

The first reports said only that he spoke no Italian, that he was young and that he had dark hair. But within a matter of minutes, a picture of the man accused of shooting Pope John Paul II in St. Peter's Square yesterday afternoon began to emerge, a picture of a militant Turkish terrorist, already convicted of one murder, who escaped from a maximum security prison in 1979 and then threatened in a letter to assassinate the Pope. The Turkish Ambassador in Washington, Sukru Elekdag, said after the news of the shooting had flashed around the world, ''The Turkish police have been under instruction to shoot him on sight.'' Said He Was a Student Moments after he was wrestled to the ground by pilgrims who had been standing near him, the alleged assailant told the Italian police that his name was Mehmet Ali Agca. He gave his age as 23 and said he was Turkish. He said also that he was a student at the University for Foreigners in Perugia in central Italy, but the records of the university showed that he had attended Italianlanguage classes there for only one day last month.

TO the littlest consumers, buying power means penny power. And to help youngsters from ages 8 to 14 decide how best to budget their weekly allowance, which bicycle is right for them, or what afterschool snack is the most nutritious, Consumers Union is publishing Penny Power, the nation's only consumer magazine for children. ''Kids are pretty important consumers - they spend a lot of money,'' said Rhoda H. Karpatkin, executive director of Consumers Union, the not-for-profit organization that has been evaluating consumer goods and services since 1936. But because they are children, Mrs. Karpatkin said, ''Kids are in a tough spot - they are the recipients and victims of hard-sell advertising that pressures them to buy, advertising that creates a value system, teaching kids to go for the brand names, the glitter, the pizazz.''

America's traditional dominance of a small but lucrative part of the world defense market - the manufacture of torpedoes for underwater warfare - has been challenged by a British electronics company that says it has developed a new generation of so-called intelligent torpedoes. The British development comes at a time when the navies of the non-Communist world are preparing to place orders for a new generation of torpedoes, which defense experts estimate could bring manufacturers as much as $16 billion worth of new business over the next 20 years. The challenger is the Marconi Company, which after nearly 12 years and $400 million of research, has developed a new generation of torpedoes that ''think'' as they swim, a feat that Marconi executives say is five to 10 years ahead of American technology. In general, United States makers dispute that claim by Marconi. Spokesmen for both the Gould Corporation of Cleveland and the Honeywell Corporation of Minneapolis said, however, that they could not provide details about the performance capabilities of their torpedoes because of constraints imposed by their contracts with the Defense Department.

The medical information on the shooting of Pope John Paul II, although incomplete, showed that the most serious damage was done to the intestines. Three sections of the bowel, or intestines, were removed in surgery, which was termed successful, at the Gemelli Hospital in Rome. A second operation will be needed to reconnect portions of the bowel that were surgically severed in a procedure called a temporary exclusion colostomy, which allows removal of bodily wastes through an opening of the colon part of the bowel outside the body. The Pope received about six pints of blood, the equivalent of about 60 percent of his total blood volume. Surgical repair of the bowel is common in gunshot wounds to the abdomen, and a temporary colostomy is often necessary in such injuries. Recovery is often complete, provided complications do not develop.

President Reagan is prepared to compromise on the size of his tax cut because of the unsettled financial markets, a senior White House official said. However, the President, who proposed a three-year, 10 percent-a-year reduction in tax rates, would not give way on the concept of a multiple-year break, the official said. He labeled the alternative proposed by Representative Daniel D. Rostenkowski for a one-year, $28 billion cut unacceptable. (Page D1.) Treasury Secretary Donald T. Regan was questioned by skeptical Republicans, as well as Democrats, on the Senate Finance Committee when he defended the President's tax relief proposal. (D15.) The Reagan Administration's plan to trim Social Security benefits met with serious Congressional opposition. (B15.)

ONE of the most basic human instincts is the need to decorate. Nothing is exempt - the body, the objects one uses, from intimate to monumental, and all personal and ceremonial space. It is an instinct that responds to the eye, for pure pleasure; to the rules of society, for signals of fitness and status, and to some deep inner urge that has been variously described as the horror of a vacuum and the need to put one's imprint on at least one small segment of the world. Embellishment is an irresistible and consuming impulse, going back to the beginnings of human history. More than just a way of changing or improving a surface or a setting, it is meant to bring about artful and magical transformations that evoke surprise, delight, even awe. All early ornament was tied to the supernatural and sublime. The decorative cycle parallels civilization; there is a line that goes right through ancient cave paintings to contemporary graffiti, with the entire history of the decorative arts in between. Probably the strongest motivating force is the simplest: the inability of almost everyone to ever leave well enough alone. The temptation to fill a blank space is common to all; a child will scribble on a wall, and the arbiter of taste and fashion will decree those decorative parameters that establish the charmed circle of social acceptability.