What was going on when I was born?

PRESIDENT REAGAN paused a few minutes in the chambers of the Speaker of the House last Wednesday night before making his State of the Union Address. Typically, he passed the time not in solitary reflection but swapping jokes and stories with Congressional leaders, downing a glass of Perrier to wet his throat. Others found him in an easy, genial mood. That infectious buoyancy soon gave a lift to his performance before the television cameras, and bolstered his confident promise of ''a second American Revolution.'' In a classic bit of political theater, the President laid claim to having changed the nation's assumptions about government - ''forever I hope.''

AT first glance, it appears to be an ordinary playroom, similar to those found in most schools or institutions. Jack-in-the-boxes, toy clocks, musical instruments and hundreds of other popular children's toys are neatly arranged on shelves, ready to be set into motion by eager children. Other toys, with missing or broken parts, sit in a pile in the corner of the room, awaiting repairs. Upon closer inspection, certain differences become apparent. All of the toys in the room - known as the United Cerebral Palsy of Westchester/Adriel and Evelyn Harris Toy Library for the Disabled - have been adapted, with the addition of special switches, to meet the needs of children and adults who have severe handicaps and would otherwise be unable to work the knobs, pulls and buttons used on ordinary toys. ''We are the first toy library that I know of in the United States to deal with the severely disabled,'' said Martin Stone, program coordinator of United Cerebral Palsy of Westchester, in Rye Brook, where the toy library is located. Established in 1982, the toy library and its two mobile units lend toys, free of charge, to 2,000 handicapped children and adults at 150 locations throughout the New York City area.

WHEN one of the Island's leading aerospace concerns, the Fairchild Republic Company, a year ago built the last A-10 Thunderbolt II attack plane for the United States Air Force, it was as if a dark cloud had draped the sprawling complex in Farmingdale. But tomorrow, the 54-year-old aerospace manufacturer will roll out the first of a new line that promises to bring relief from employee layoffs and nose-diving earnings: the T-46A jet trainer. The twin-engine, two-seat aircraft is the first of a potential 650 planes that Fairchild is to produce for the Air Force to replace Cessna's T-37 as the basic trainer for student pilots. It is the first aircraft to be designed using technology developed under Fairchild Republic's five-year, $100 million modernization program, which began in 1982. Recalling when Fairchild Republic was awarded the T-46A contract in July 1982, Dr. Robert J. Sanator, the company's president, said: ''It was a very big win for us then. We saw it as a program that would carry Republic as a viable outfit well into the 90's.''

When the restaurant now being created in Manhattan's Carlton House opens its doors later this year, some patrons, no doubt, will recognize its stained-glass ceilings, deep-red upholstery, fleur-de-lis sconces and framed Sem cartoons as signatures of Maxim's de Paris, one of France's best-known restaurants. Work is now in progress to recreate the turn-of-the-century Parisian eating establishment in a 2,100-square-foot space on the first and second levels of the Carlton House, a residential hotel on Madison Avenue at 61st Street.

TWO seconds remain on the clock of the oddly - shaped scoreboard that hangs high above center court in Boston Garden. Time has been called with the Portland Trail Blazers ahead, 127-126. In the huddle, Coach Jack Ramsay of Portland, certain the Celtics will go to Larry Bird for the last shot, is mapping a defense. Play resumes, Dennis Johnson inbounds the ball to Bird and the 6-foot-9-inch Celtic forward, double- teamed, hits a 20-foot fallaway jumper from the left corner at the buzzer. Another Celtic victory and yet another defense that failed to stop Bird.

It is no coincidence, says Warren Avis, a Michigan real-estate developer who last month paid $7.8 million for two small commercial buildings on West 52d Street, that his new neighbor is the ''21'' Club. ''The idea of being next to '21' sold me,'' said Mr. Avis, who will build a 28-story condominium residence in the space now occupied by buildings at 23 and 25 West 52d Street.

Brokerage stocks, among December's worst performers, were the biggest gainers in January's rally: as a group, their prices rose 29.4 percent, according to figures compiled by Standard & Poor's. That should be no surprise, since brokerage stocks have a high ''beta'' factor - that is, when their prices do finally rise, they do so at a higher rate than market prices in general. Historically, they climb at a ratio of about 1.85-to-1 relative to the market as a whole, says Perrin H. Long Jr., an analyst with Lipper Analytical Services. That makes brokerage stocks an attractive investment in a rally, Mr. Long said. ''If you thought the market was going to go up another 200 points on the Dow, why not buy the brokerage stocks, instead of trying to figure out which stocks would go up?'' he said. Mr. Long said the rally meant that brokerage firms, which posted mostly disappointing fourth-quarter results, sould have higher first-quarter earnings. But he warned that brokerage stocks decline more than the general market in a time of falling prices.

A few years ago, when Ferdinand Gottlieb built Washington's Headquarters, the first condominiums in Dobbs Ferry, N.Y., he did so over the objections of some residents who felt that the town houses would be an intrusion on the village's single-family style. Now, in an effort to make the homes in his new seven-unit condominium project in the Westchester County community look as much like single-family residences as possible, the architect and developer has designed what he calls an ''experiment'' in clustered housing.

After decades of resistance to multifamily housing in Darien, Conn., the Fairfield County village agreed two years ago to relax its rigid zoning ordinances and allow apartments to be built in nonresidential sections of the community. One area selected specifically for the development of housing for the elderly was the property where the old Town Hall stands, vacant and unused, at Post Road and Academy Street.

ALL last week, in his budget message, annual economic report and State of the Union address, President Reagan laid out the game plan for his second term. He means to consolidate the conservative revolution in public policy - he calls it a Second American Revolution - that he began four years ago. In fact, the Reagan revolution, which he suggests is a reprise of George Washington's, is meant to be the counterstroke of the Roosevelt revolution of the 1930's. Where Franklin Roosevelt sought to overcome the problems of the Depression by increasing the economic and social role of the Federal Government, Ronald Reagan has attacked ''stagflation'' - that combination of stagnation and inflation that dogged the economy in the 1970's - by cutting the role of Government and by relying increasingly on what he calls ''the magic of the market'' to generate strong economic growth. To date, Mr. Reagan's economic policies look like a striking success. The economy's performance was a major - perhaps the major - factor in the President's landslide re-election, and that victory has emboldened him to stay the course he began in 1981. As he envisions that course, a free-market economy, with steady growth and low inflation, will emerge from the changing tax system, from the deregulation of major industries and from cuts in long-standing Federal subsidies in many areas, including agriculture, housing and medical care.

A CASE now before the State Supreme Court may be instrumental in making it easier - or more difficult - to win suits against the government. In Kolitch v. Lindedahl, the court has been asked to review an Appellate Division decision that said the state's Department of Transportation could be held liable for putting a 50- mile-an-hour speed-limit sign 200 feet before a dangerous turn in a road, when the safe speed limit might have been 30. The extent to which the decision is modified, if at all, will greatly affect the way in which other courts in the state interpret exceptions to government liability immunity in the law known as the Tort Claims Act. The act applies in all suits for personal injury or property damage brought against the state or local governments or their employees. It is meant to immunize government from any liability for what its employees do or fail to do, except where the act specifically states otherwise.

Walters NamedTo U.N. Post Conservatives were also happy not to lose an outpost at the United Nations. To replace Dr. Kirkpatrick as chief delegate, the President named Gen. Vernon A. Walters, who has a similar outlook though a greatly different background and training. Dr. Kirkpatrick is an academic, General Walters a military, intelligence and language expert who has spent much of his 44-year career on discreet, often shadowy missions in various trouble spots around the world.