What was going on when I was born?

Uniting the followers of New York's pro football teams for one glorious Sunday, the Jets swept themselves and the Giants into the playoffs yesterday with a crushing 28-3 victory over the Green Bay Packers. For Jet fans and players, few days have been more memorable. The Jets were wild-eyed before the game in a raucous locker room; when it ended, in the swirl of the December winds at Shea Stadium, the fans were the ones who shouted and leaped, hundreds charging onto the field, dozens trying to tear down one of the uprights. It took the Jets, who had started off so badly this campaign, until the final weekend of the regular season to determine their fate - by winning, they qualified for the National Football League playoffs for the first time since 1969 and the Joe Namath era. Green Bay was competing with the Giants for a National Conference wild-card spot, so by disposing of the Packers the Jets guaranteed that for the first time both New York teams would be in the playoffs.

The last weekend before Christmas - traditionally the busiest period on the retail calendar - drew hordes of shoppers but generated spotty sales, retailers in the New York area conceded yesterday. A survey of stores showed that the flow of customers developed late and sales of more expensive merchandise were lagging. And although many stores had already reduced prices, shoppers interviewed Saturday and yesterday complained of high prices and said they were spending less on gifts this year. A shopping tour of the area found an uneven flow of shoppers and considerable comparative shopping. Many people - about 12 out of 13, by one count - walked out of stores without making a purchase. And more than half the store clerks had no customers.

In nearly two years since the most savage prison riot in American history, improvements in conditions and security at the state penitentiary here have reportedly been gained grudgingly, if at all. Lawyers, former guards, prison rights advocates, corrections officials and outside experts say this is the case even though the state has poured large amounts of money and manpower into its prison system. A new commissioner has taken over the Department of Corrections, seven law-enforcement and legislative investigations are under way and the system has been under the constant scrutiny of a lawyer assigned to measure compliance with a Federal judge's reform orders. Efforts to improve the prison have had wide public support. Although the prison authorities say that they are improving their control of violence, it persists nonetheless. Since the riot in February 1980, in which 33 inmates were tortured and killed by fellow prisoners, nine inmates and two guards have been slain at the penitentiary.

''IF it wiggles, I'll hit it,'' Beasley Reece, the senior citizen of the Giants' defensive backfield, had said early in the week before Saturday's must-win game against the Dallas Cowboys. Now, he had come out on the field for the pregame warmups and a few of the Cowboys sauntered over to their former teammate. Reece was pleased by what he heard. ''Tony Hill, Drew Pearson, a couple of the others, they all made mention of how we had been hitting,'' he said. '' 'You guys are flying all over the field,' and 'You guys are hitting everything that moves,' those kind of things. It's an image we're proud of.'' It's an image from deep in Giant history. The last time the Giants won a National Football League championship was 25 years ago, when they had a rookie linebacker named Sam Huff and the team's fans invented the cheer of ''Dee-fense.''

State officials and nursing home associations reacted with dismay and bafflement yesterday to the Reagan Administration's proposals to relax or repeal many Federal regulations affecting the treatment of patients in long-term care facilities. The officials said that New York's nursing home standards, upgraded after a series of scandals in the 1970's, were now the most stringent in the nation and would not be affected by changes in the less strict Federal law. But they said the Federal Government was setting a bad example for the quality of care to the aged and sick. The director of the Greater New York Health Care Association, the largest group of privately run nursing homes in the state, said he could not understand how money would be saved by the Reagan proposals. The proposals are part of an effort to eliminate what the Administration views as costly, unnecessary regulations.

UP in the Shea Stadium stands behind the end zone, a young man in a green and white jersey was shouting, ''The Jets are in the playoffs,'' and next to him a teen-ager in a blue and red stocking cap was yelling, ''The Giants are in the playoffs.'' For two decades, the Jets and the Giants and all their followers have been rivals. But yesterday the twain met. When the Jets crushed the Green Bay Packers, 28-3, the Jets not only qualified for the Super Bowl playoffs, but they also put the Giants into the playoffs. After a generation of wondering what to do about two pro football teams that were jokers, New York suddenly has two wild cards to cherish.