What was going on when I was born?

''I have returned on my free will to join the ranks of those struggling to restore our rights and freedoms through nonviolence.'' - Benigno S. Aquino Jr., in a statement prepared for his return to the Philippines. (A8:1.)

Most of the afternoon was a contrast, power pitching against finesse pitching. Dave Righetti, on the mound for the Yankees, was cutting his way through the California order with fastballs. Geoff Zahn, for the Angels, was flirting with the Yankees, skipping out of jams with off-speed pitches and breaking balls. In the end, though, offensive power was the decisive factor. Ken Griffey, with two out in the bottom of the ninth, lashed Zahn's 0-1 pitch to right field for a two-run single to give the Yankees a 2-1 victory yesterday in front of 50,896.

They had been fishing for two hours off Sandy Hook, N.J., yesterday, and the hardest thing hitting the deck of the 110-foot Palace II was the sun's rays. Blues and fluke were what they were going for, with most of the 60 people aboard after fluke. At each new fishing spot, the engines were cut, the horn was sounded and the four dozen fluke fishermen lowered their baited hooks to the bottom and waited for something to happen. It seldom did.

International A single shot in Manila killed President Ferdinand E. Marcos's strongest political rival. The opposition leader, Benigno S. Aquino Jr. was shot within minutes of his return home from three years of self-exile in the United States. He was shot while being escorted by military guards off a plane at Manila International Airport, where thousands of his followers were waiting. Maj. Gen. Prospero Olivas, the police chief, strongly denied that a security detail had carried out the slaying. (Page A1, Column 6.) Filipinos gathered in a Boston suburb at the home of Corazon Aquino, wife of Benigno S. Aquino Jr., some arriving from Filipino exile communities in Dallas, New Orleans and New York. Mrs. Aquino said she felt ''fatalistic'' about her husband's death. (A1:4.)

At 1:20 yesterday morning, a boisterous crowd had gathered around a three-card monte game at the corner of Broadway and 44th Street. A young woman who looked to be an out-of- towner - her eyes wandering up and down the Times Square neon, her tailored suit like that of a theatergoer - noticed the excitement and stepped over to watch. As she did, two young men nudged her. One came from the left, the other from the right. A third, wearing a bright green baseball cap and white sneakers with green laces, reached from behind, grabbing the wallet out of her brown vinyl purse. Wallet in hand, he scurried down 44th Street toward Eighth Avenue. But he did not get far. The woman, Police Officer Mary Ann Millard, was a decoy. The youths were arrested within minutes and charged with grand larceny. Handcuffs were snapped around their wrists, and the wallet, which contained only $1, was put back in the purse to wait for another thief. The police declined to identify the youths because they were minors.

Putting aside a longstanding aversion to winning adherents, Jewish leaders across the spectrum of Judaism have been working to kindle an active interest in the religion among uncommitted Jews. Jewish leaders in the Reform, Conservative and Orthodox branches said they had been acting in response to what they see as an alarming erosion of Jewish ethnic and religious identity. This erosion has created a climate of crisis over Judaism's future, they said, and has paved the way for dramatically more aggressive approaches. ''In a way, Jews have become evangelicals,'' said Dr. Irving Greenberg, director of the National Resource Center in Manhattan. In a competitive society like America, he said, ''all religions have to broadcast their message - if they don't, they get nowhere.''

HIS manner was casual and his mood upbeat, a departure from the days when Reggie Jackson reigned in the Bronx and storms of controversy often swirled about him like hot-dog wrappers and empty soft drink cups caught in a Yankee Stadium whirlwind. Perhaps it is an indication that Jackson has come to terms with what has been his most disappointing season. Perhaps he does not want to betray his emotions in a city where the memories are so bittersweet. Jackson has heard and read the assessments of others as he makes the rounds of the American League with the California Angels. There are the fans and reporters and baseball people who believe that Mr. October is in the December of his career. It is likely that nowhere would his presumed demise be trumpeted more than in New York, where the Yankees allowed him to become a free agent after the 1981 season and then, much to their embarrassment, watched Jackson hit 39 home runs and lead the Angels to the American League West championship last season. ''A few people have written my eulogy,'' Jackson said. ''It hasn't been vicious, though. I'm hitting .210, so how can I get upset when people say this is the end?''

World swimming records often look easy. Few have looked as easy as the one set today in the rain in the Pan American Games by Rick Carey, a 20-year-old Texas junior from Mount Kisco, N.Y. For the third time in 16 days, Carey smashed the world record for the men's 100-meter backstroke. In the final, he took command at the start, hit the turning wall clearly in front and raced to an almost three-length victory over Dave Bottom of Danville, Calif. Carey's time was 55.19 seconds.

Governor Cuomo said yesterday that surprise state inspections of two New York City hotels housing displaced people had found ''mind boggling'' health conditions. He said he had ordered the State Health Department to provide emergency food and medical care for families there. The Governor also ordered an immediate investigation into conditions at the two hotels and the 50 or so others citywide that house families who have been forced from their homes because of fire, eviction or high rents. ''It is theoretically a city management problem, but it is the kind of problem where you don't draw those nice lines,'' Mr. Cuomo said. ''I said do everything that needs to be done immediately. Forget about who you charge it up to. I said get food in there.''

A 21- year-old woman who neighbors described as shy and afraid to stay alone was found slain Saturday night in her parents' home in Great Neck Estates, the police said today. The woman, Pamela G. Sharon, was found lying nude in a hallway of 14 Oak Drive, the four-bedroom stucco house in the quiet, well-to-do neighborhood that she shared with her parents and two older sisters. She had apparently been struck on the head with a blunt object, the police said.

As a writer who specializes in baseball, especially its shadowy early history, Dick Thorn has been a familiar figure at the New York Public Library. That's because the library has what Thorn and others consider one of the most important resources for baseball research, the Albert G. Spalding collection of early baseball diaries and scrapbooks.

He has lived the life of a boxing champion, complete with limousines, room service and luxury hotel accommodations, and now, after years of comparative deprivation, Roger Stafford is looking to regain the championship life by doing something he's never done before - becoming a champion. Stafford, a 28-year-old welterweight who is scheduled to meet Donald Curry, the World Boxing Association titleholder, in Marsala, Italy, on Sept. 3, has never held a title or even had a championship fight, but he got a taste of life at the top after he left the service in 1976 and hooked up with a Marine Corps buddy. The friend was Leon Spinks, and it was as a member of the Spinks entourage that Stafford learned what it was like to be a champion. It was, to be sure, a brief lesson. Stafford, who was present when Spinks won the heavyweight title from Muhammad Ali in Las Vegas on Feb. 15, 1978, was also present in New Orleans seven months later when Ali won it back.