What was going on when I was born?

When residents of the Connecticut River Valley village of Chester (pop. 3,140) do spring cleaning, they clean up more than their own 18th-and 19th-century houses. They also make sloppy neighbors clean up yards cluttered with trash and rusty old cars.

AFTER a long winter in which high interest rates kept buyers out of the housing market, renovators of Manhattan cooperatives and condominiums are trying to lure them back with financial inducements that are worth thousands of dollars. The developers are offering up to 18 months of free maintenance reduced purchase prices, subsidized interest rates, their own money for financing and special while-they-last sales on specified units. If the financial packages seem novel, so are some of the apartments. As the largest number of renovated units to come on the market in one period, these units. are, in effect, creating a whole new market. They are hybrids of the apartment with lots of services and conventional space and the loft with unusual space and few services. One builder calls it the "luxury-loft" market.

UPPER SADDLE RIVER IN THIS wealthy white-collar community of 8,000, kindergarteners who still have trouble buttoning their coats and tying their shoelaces are as handy with microcomputers as they are with wooden building blocks. Here, public-school pupils have gone beyond the three R's and have added a C - for computer literacy. ''The future is here now, and these students have to be prepared,'' said Thomas Benson, Superintendent of the 1,100-student school system, echoing the sentiments of parents and teachers alike. With moral and financial backing from the Board of Education, they contend that the use of computers as a teaching tool is a valuable aid in preparing youngsters for careers in computer-related fields, as well as introducing them to a system capable of providing unlimited information at the touch of a button. For example, at the Reynolds School (Grades K through 3), each of the 292 pupils has mastered the simple process of using computers in studying mathematics, science, reading and social studies. The feeling in the school is that computers as a teaching tool of the future will be the rule, not the exception, replacing aids and skills traditionally presented in book form and on a blackboard.

CHRISTOPHER WALKEN, John Kenneth Galbraith, Joyce Carol Oates, the British National Rugby team, 1,100 show riders and horses, and 16 women's college rowing teams will participate in events, seminars and performances that promise to make this Connecticut spring and summer exceptionally bright and lively. Mr. Walken, who lives in Wilton, makes his first foray onto the legitimate stage in some time, tackling two formidable roles at the American Shakespeare Theater in Stratford - Hotspur in ''Henry IV, Part I,'' July 6 through Aug. 1, and the title role in ''Hamlet,'' Aug. 3 through Sept. 5. He will be joined in the first production by Richard Thomas as Hal and Roy Dotrice as Falstaff. In the second, Anne Baxter will play Queen Gertrude, Hamlet's mother; Fred Gwynne will be her husband, Claudius; Roy Dotrice and Richard Thomas are cast as Polonius and Laertes, respectively. Mr. Galbraith and Miss Oates are two of several well-known individuals who will be involved in a pair of two-week June seminars at the University of Hartford - one on economics, the other on interpersonal relationships and the sexual revolution. Alfred E. Kahn, Thomas Sowell, Paul W. McCracken, Yale Brozen and nine other economists will explore supply-side economics, protectionism, deregulation, Social Security and antitrust policies. Miss Oates will share a seminar titled ''New Images of Love'' with Gail Sheehy, Alex Haley, Shere Hite and other authors, psychologists, sociologists and clergy. Both courses may be taken for credit or audited.

The great performances of our theatrical past stand out like meteor trails in the night sky, fiery arcs of passion and artistry that retain their glow across the decades. One of the brightest performances ever to light up Broadway was that of Judith Anderson in ''Medea,'' of which Brooks Atkinson wrote in 1947: ''It would be useless now for anyone else to attempt the part. Using a new text by Robinson Jeffers, she set a landmark in the theater ....'' Now, 35 years later, another actress is about to test that judgment. ''Medea'' returns to Broadway tonight at the Cort, with Zoe Caldwell in the title role of the barbarian priestess who exacts a savage revenge on her faithless husband by murdering their two children. What makes this revival of Euripides' bloody Greek classic a remarkable event is the presence in the cast of none other than its original star. Dame Judith Anderson has come out of retirement to play the vital supporting role of the Nurse to Miss Caldwell's Medea, and, more than that, to share with her some of the insight and artistry that helped her claim the part as her own for so many years. When the curtain rises on ''Medea'' this evening, the audience will witness the passing of a torch from one theatrical generation to another.

Chanting ''We want freedom!'' ''Release Lech Walesa!'' and ''Down with the junta!'' a throng of about 30,000 marched through Warsaw's Old Town today to show support for the suspended Solidarity union and opposition to military rule. The unauthorized demonstration was so large that it caught even its organizers by surprise. It was by far the biggest show of resistance since the military crackdown four and a half months ago. The enthusiasm of the march was in dramatic contrast with the staid regimentation of the official parade only a few blocks away to commemorate May Day. The two gatherings seemed roughly equal in size, but one was spontaneous and the other compulsory.

DANIELSON THE oldest, John, is 18 now. He knows about Vietnam. His father, Armand Comire, was in and out of military hospitals while John was growing up. Danielle, the other child in the family, is only 4 years old. When she grows up, Mr. Comire had figured, she'll know about Vietnam only from the history books, which he says aren't enough, and the movies, which he doesn't like, and from the scarred story that shrapnel wrote all over him. Mr. Comire, who is 38, thought there ought to be something more lasting to give her when he dies (which one of his doctors said should have happened years ago). It was for Danielle, he said, that he asked last year for the Purple Heart he had earned in 1966 but never received. And on April 12 he got it, pinned on by a brigadier general in the chambers of the Connecticut State Senate.

The air and sea battles that erupted around the Falkland Islands throughout the day indicate that the British will not waste the tactical momentum won by the bombing of the islands' two airfields early this morning. In the present situation, analysts said, there is an opportunity for helicopter landings by Royal Marine commandos to take advantage of what the analysts consider the temporary confusion and wide dispersal of the Argentine defenders. The Argentine force at Darwin, near Goose Green airfield, which is estimated at one battalion, could be one target for early attack. Britain's apparent ability to establish air superiority around the Falklands is a major reason for believing that it now intends to push rapidly toward establishing bridgeheads on East Falkland.

THE lawyers for all sides are ready, the technical experts have framed their conclusions, and on Tuesday the Long Island Lighting Company will square off against its opponents and try to prove to Federal regulators that its Shoreham nuclear power plant is safe enough to operate. But even as the combatants bob and weave at the hearings in Riverhead, it appears that two of the most important issues affecting the future of the Island's first nuclear power plant - emergency planning and quality control -will be decided largely outside the formal licensing process. Although Federal regulations do not require it, Lilco has agreed to allow independent experts to examine the Shoreham plant and make certain that it has been built properly. Suffolk County, meanwhile, has scrapped a nearly completed plan for dealing with emergencies created by accidents at Shoreham and has set up a panel of experts to write a new one.

HAUPPAUGE WITH Long Islanders demanding tough anticrime measures, the courts have responded by sending more prisoners to jail and for longer periods of time. This has left the Island's aging prison system overcrowded, with no cure in sight, unless additional prison facilities are provided. Nassau County, under pressure from a Federal judge, is adding more jail space. But Suffolk County, left on its own, has failed, at least so far, to meet the challenge.

HOWARD GREENE had spent a long day in Philadelphia, holding meetings for the St. Regis Paper Company that went on into the evening. Like most up-and-coming young executives - Mr. Greene was 34 years old - he was torn between staying overnight or driving home. He decided to return to Montclair. A block and a half from home, Mr. Greene remembers, he saw headlights speeding toward him on his side of the road. The impact sent his car flying through the air, and he believes he lost consciousness after it became airborne.

For its 80th birthday this year, the Flatiron Building, once the soaring symbol of New York's pre-eminence, is getting a new neighbor, a 30-story apartment house that will compete with the tower's prowlike domination of Madison Square's southern skyline. At the same time, a devastating moment in the neighborhood's history will be commemorated.