What was going on when I was born?

At the moment this is being written I haven't yet seen any of the 26 programs in the 19th New York Film Festival that opens at Lincoln Center Friday night with the English ''Chariots of Fire.'' A quick rundown of this year's festival entries seems to indicate that there are more unknown directors than at any time in the recent past. There are - true - films by Francois Truffaut, Michelangelo Antonioni, Jacques Rivette, Andrzej Wajda, Louis Malle and Eric Rohmer, but most are by new directors or by directors like Maurice Pialat and Wim Wenders, who still have not yet found the audiences they deserve this side of the Atlantic. About most of the entries I am, I suspect, as much in the dark as any other reader of The Times who, last Sunday, studied the festival programs for information about particular films, such as ''The Mystery of Oberwald'' (''Cocteau's play functions simply as the libretto for Antonioni's tonal experiments in film and video color...''). That annual announcement ad is always intimidating, not only because one can never be sure one understands what one is reading (what, for example, does ''a wayward display of idiosyncratic sympathies'' mean?), but because on e knows that, time being what it is, it's impossible to see absolutely everything. But this is what keeps the festiv al alive and why, each year, so many of us scramble to see films by unknown directors with as much eagerness as films by those directors we know and admire.

If you own a home and plan to keep it, have one you want to sell, or are looking for one to buy or rent, chances are that the new tax law will benefit you directly. For many homeowners, those whose houses are their most important asset, the biggest break will most likely come in the form of the changes in the estate tax, which effectively eliminate Federal death taxes for all but the very rich and do away with taxes on bequests to a spouse. Other major changes in the Federal tax laws signed by the President last month include the following: * A liberalization of the gift tax, allowing one spouse to give an unlimited amount of personal property to the other tax-free. * A $25,000 increase in the capital gains exclusion for persons 55 years of age and older, which will allow those who qualify to exclude from capital gains taxes up to $125,000 in profits from the sale of a home. * The introduction of tax-exempt savings certificates, intended to attract money to the ailing thrift institutions, but ultimately expected to benefit home buyers by increasing the supply of mortgage money.

YONKERS ATHIRD plan for the county to come to the aid of this city's beleaguered budget surfaced last week and immediately became entangled in the thickets of election-year politics. The first two plans included one for $1.1 million in county funds proposed by Alfred B. DelBello, the Democratic County Executive, and a subsequent proposal for $1.7 million by Andrew P. O'Rourke, the Republican Chairman of the county's Board of Legislators. Now two Republicans on the City Council, joined by a Republican County Legislator from Yonkers, have come up with a third alternative. It involves the county's prepaying to Yonkers in its present fiscal year 20 years worth of payments in lieu of taxes on a local bus-maintnenace facility. The amount, its sponsors say, would be $1.1 million.

Noble Nashua proved it was no fluke that he ran the fastest mile in the history of Belmont Park three weeks ago by carrying his speed an extra quarter-mile yesterday and winning the $400,000 Marlboro Cup by 3 3/4 lengths at Belmont. Pleasant Colony, considered a shoo-in as best 3-year-old and horse of the year, seemed to lose his grip on both honors as he finished a dull fourth behind Noble Nashua, the only other 3-year-old in the field of eight. But immediately after the race, one of Noble Nashua's owners said the colt was through for the year, and it is unlikely that Pleasant Colony will be denied those awards on the basis of one race. ''I am in favor of running him next year,'' said Carl Lizza, the co-proprietor of Flying Zee Stables, which owns Noble Nashua. ''He will not run a ny more this year.''

WASHINGTON HIGH interest rates, the economic handicappers had thought, should have shut down the economy long before now. It hasn't happened. Not that things are all that bright. The securities markets are reeling. Detroit is depressed, and so are the homebuilders. Unemployment has remained around 7 percent for almost a year and a half. And over all, the economy is no better than sluggish. By the second quarter of 1981, the nation's gross national product, after adjustment for inflation, was just slightly above the level of the first quarter of 1980, and third quarter, according to preliminary figures released last week, will be no better. Yet except for the short, sharp recession of 1980, the economy has shown it can evade a slump longer than the experts, who started talking about a recession in 1979, ever dreamed. And many economists now contend that the slump of 1980 was an aberration - the price of the Carter Administration's credit controls. Without the controls, they say, the economy would have muddled along with continued high interest rates, just as it has done this year.

SECURE in the sense of its own specialness, Rutherford will begin celebrating its 100th birthday today with a spry 91-year-old, rather than a teen-age beauty, as the centennial queen and with its status as a saloon-less, alcoholically ''dry'' community still intact - although somewhat breached by beer. To the passerby - and there have been hordes since the Sports Complex went up in the Hackensack Meadowlands next door - the specialness will not be readily apparent, in either the celebration or in the community itself. But to those who grew up here, there has always been the feeling that, however difficult to spell out, this trapezoidal slice of suburbia between the Passaic River and the Meadowlands was different from its neighbors. ''It's a nice town, and I'm really happy that I'm here,'' Elvira Liesegang said the other day. When the people running the centennial celebration set out to find a queen, she recalled, ''it came to me that this is historical.'' And, she decided, she was historical, for she has lived here since 1923.

PURCHASE OPENING today at the Neuberger Museum of the State University of New York here is a formidable display that should be not just a howling success but a whirring, clicking, chiming, humming, even melodic one, too. ''Soundings'' is the show's name, the use visual artists have made of sounds (actual or implied) its game. Conceived and orchestrated by the Neuberger's director, Suzanne Delehanty, the survey is the first of its kind to be staged in the United States. It will run thro ugh Dec. 23. Crucial services were rendered to the enterprise by Douglas Caulk, manager of the museum; Michael Reed, technica l consultant, and the 10state university students who labored on the installation. The noless-crucial funds were supplied by the Nat ional Endowment for the Arts, the Roy R. and Marie S. Neuberger and t he Miriam and Ira D. Wallach Foundations and the Westchester Arts Fund of the Council for the Arts in Westchester.

HARRINGTON PARK THE future bills of the Hackensack Water Company will present, in stark dollars and cents, the financial legacy of the 1980-81 water shortage: A 47 percent increase for tens of thousands of homes and industries that were forced by state law to save water from last September to May. The higher rates will generate $21 million in new income for the company. Both it and the state's Board of Public Utilities, which approved the increase on Sept. 3, emphasize that it is in the best interests of Hackesack Water's 800,000 customers to pay the money. They say that new supplies can be developed with it, ending the company's chronic water shortage and freeing customers from future threats of mandated conservation. The new rates, so the argument goes, are the best and only way to end the ''drought'' and prevent future ones.

It has been said that all good things come to those who wait, and that philosophy worked well today for the Boston Red Sox. They patiently waited for Ron Guidry to leave the game, then scored seven runs in the eighth inning and an 8-5 victory over the Yankees. Guidry, who has an 8-2 career record against Boston and had three victories in three starts at Fenway Park, left after seven innings with a 5-1 lead. ''I had a good shot at it,'' Guidry said about his 12th victory, ''but I never take 'em until they're finished. Especially here. Anything can happen here.''

IF April mixes memory and desire, as T.S. Eliot said, surely October produces an equally heady brew, distilled from the reds and golds of the landscape, the first sniff of mothballed twe ed, the lastbrilliant ski es before winter, a nip in the air and the anticipation of a new seas on of entertainment. Adding to the enjoyment of autumn in the state will be diversions that include a glide past the fall foliage in a canoe, a harvesttime visit to practitioners of viniculture and a contest called the Pumpkin Open. And now that the 142-acre Danbury Fairgrounds have been sold to the Wilmerite Corporation of Rochester for transformation into a $100 million shopping mall, there may be many more people than the usual half-million who will want to attend the last of the 112 Danbury Fairs from Oct. 3 to 12. Famed throughout the country and abroad as the granddaddy of typical American country fairs, this one, according to Fred. G. Fearn, president and general manager, ''will be the best ever.''

HARTFORD GOVERNOR O'NEILL'S 11-day trade mission to France, West Germany and Britain, to begin Friday, will mark the first time a Connecticut Governor has gone abroad specifically to seek additional foreign investment for the state. Economic development officials say that the Governor's presence is designed to impress executives of foreign companies and to insure that the state delegation will gain access to high-ranking officials. ''In this type of business, as in any type of sales, it makes good strong sense to have a senior official go,'' said John J. Carson, Deputy Commissioner of Economic Deve l opment. The delegation will target metal-working and electronics operations and will meet with several European manufacturers who have expressed an interest in opening Connecticut plants, said David Driver, a spokesman for the Department of Economic Development. He declined to identify the companies.

''We have come too far, struggled too long, sacrificed too much, and have too much left to do, to allow what we have achieved for the good of all to be swept away without a fight. And we have not forgotten how to fight.'' -Lane Kirkland, president of the AFL-CIO. (1:6.)