What was going on when I was born?

FOR almost a century, Columbus Circle has played the tortoise to the hare of Manhattan real-estate development, moving in brief bursts of energy only when expansion of other sections of the borough faltered. Now it is undergoing a period of rapid growth that may carry it nearer the long-ago expectations of some city planners who predicted that it would be the eventual hub of the city. The centerpiece is the multimillion-dollar twin-towered complex of offices, hotel, condominiums and stores that Boston Properties is planning on the site of the New York Coliseum. But dotted around it in the area bounded by Broadway, Lincoln Center, 55th Street and the Hudson River are at least 15 other projects in various stages of development. Indeed, in the now updated view of some real-estate developers, the Columbus Circle area - which the Dutch first named the ''Valley of the Flowers'' - is blossoming into a future that could make it one of Manhattan's prime residential and commercial neighborhoods.

ATTRACTED by Federal and state tax credits and the possibility of saving on energy costs, thousands of Long Islanders have built or are thinking of building ''solar'' rooms. But in many cases, consumer affairs officials warn, the buyer may be getting a lot less than he bargained for. Dealers say they expect a great deal of business this fall as people seek to build before the Dec. 31 deadline for Federal and state tax credits for solar energy systems. The combined 55 percent credit (40 percent Federal, 15 percent state) can bring the cost of a $6,000 solar room down to $2,700.

FOR the last decade, things were good for the Marriott Corporation. Few sizable companies in any business can grow at 20 percent year after year, but the aggressive company from the suburbs of the nation's capital made fast growth its credo. Marriott's business hotels sprouted in choice suburban, airport and downtown locations and the company - and its industry - seemed to be on a never-ending growth spiral. But times have changed. The hotel market has become overbuilt and business has slackened. And feisty Marriott, which anticipated many of these changes, is now switching gears within the industry and taking its name where it has never been before. Next month the doors officially open on the New York Marriott Marquis, a glittering $400 million atrium hotel plunked down in tawdry Times Square. Marriott is going into the convention business in a big way and will spend over $1 billion in a coast-to-coast effort to take on the heavyweight in conventions, the Hilton Hotels Corporation. The first try has not been easy: The Times Square location is not prime territory, and a new convention center nearby, which Marriott was betting on to feed guests into its 1,877-room hotel, is still in construction and far behind schedule. Marriott executives insist that the goliath New York hotel will eventually succeed, but they concede that profits are several years away.

THOUGH the state's apple growers faced some difficulties this year, including a late frost last spring and high heat and humidity in recent weeks, most expect to harvest a hearty crop of big and juicy apples. While the crop is expected to be slightly smaller than last year's, growers say prices will be about the same and the quality better. ''The quality of our apples is fantastic, the best in several years,'' said Dr. Alan J. Grout, who runs Aspetuck Valley Orchards in Easton. He was not as enthusiastic May 8, though, when a late frost threatened to destroy most of his crop. His apple trees were in full bloom, with blossoms at their most delicate change, when the temperature reached a critical 28 degrees.

A gigantic shift on the Pacific Ocean floor jarred Mexico's west coast last week, causing devastation in Mexico City, 230 miles away. Preliminary reports said the earthquake had killed several thousand people, leaving thousands more injured and homeless. Yesterday, a White House official predicted the final total of dead and injured would be in the tens of thousands. A powerful second earthquake compounded the destruction, much of it in the capital's historic center, which rises above an ancient lakebed, an insecure footing that made the destruction worse.

Mariel Dolores Robles walked into the small, brick room hesitantly, her hand held to her face. It was a room she had hoped she would never enter. The floor was covered with dusty, battered bodies arranged in neat rows, the bodies of this city's earthquake victims. Mrs. Robles took a few steps and gasped. ''It's her,'' she said. ''It's her.''

WHILE water-use restrictions - no watering lawns, filling pools or washing cars - is a novelty of this summer's drought for county residents, water rationing has become a way of life in Shenorock, a lake community in the town of Somers. Residents here have had to cope with water-use restrictions since 1976 when the community was forced to tap a nearby lake as a water source. Shenorock has lived under a declared water emergency since July 11, 1983, when a moratorium was imposed on new building and the use of water outdoors was prohibited. Shenorock does not get enough water from the lake that it tapped almost a decade ago, and its wells do not yield enough water. To compound the problem, Lake Shenorock is beginning to fill in with silt, leaves, and other organic matter. The 15-acre lake, once about 10 feet deep, is now a muddy 4 1/2 feet.

In villages throughout El Salvador, a one-day truce halts the fighting as medical teams inoculate children against five fatal diseases. Halfway across the world, near the Aswan Dam in Egypt, a restoration team puts the finishing touches on a 20-year project to save the historic temple of Abu Simbel. On the island of Cyprus, peacekeeping troops stand guard along the line separating Greek and Turkish Cypriots. And in a dark, windowless conference room on the far East Side of Manhattan, delegates debate the morality of corporations doing business in South Africa. These four programs are only a few of the tens of thousands of operations organized or sponsored by the United Nations, which is celebrating its 40th anniversary this year.

When a 30-story condominium called the Columbia went up on Broadway and West 96th Street in 1982, the seeds of further development for the Upper West Side were sown. The success of that effort led to other commercial and residential projects along Broadway and prompted revitalization on sde streets as well.

He was fighting against time and diminishing skills, and on this occasion, Larry Holmes also took on the memory of a popular heavyweight champion whose record he was trying to equal. Michael Spinks, a bold young light heavyweight, used these factors to his advantage tonight, accomplishing what no one in his weight class had done before. In the process, Holmes left the ring a loser for the first time in his professional career. Spinks became the first light heavyweight to win the heavyweight title and also prevented Holmes from equaling Rocky Marciano's record of winning 49 consecutive bouts without a defeat. In a closely scored but unanimous decision, Spinks simply outpunched the 35-year-old Holmes, who was the International Boxing Federation champion and had held one version of the title or another for seven years. That was the second-longest reign, after Joe Louis's.

President Reagan, advised that the Mexican earthquake disaster is much worse than originally feared, offered substantial American aid today and moved to help organize a worldwide relief effort if Mexico asks for one. ''This is going to become a historic catastrophe,'' a senior Administration policy-maker asserted today. ''We're talking about thousands and thousands of casualties and tens of billions of dollars in damage requiring a scale of recovery far beyond the capacity of the U.S. Government to provide aid for.'' ''There seems to be a need for a very substantial global response,'' he added. ''This probably transcends the scale of the Ethiopia famine.''

A FIRE last month that destroyed the Salisbury Town Hall has prompted officials in other towns to take steps to insure that their records are protected from disaster, according to Dominic A. Persempere, the state's public records administrator. ''I've been hammering at them to do something,'' Mr Persempere said, ''but now it's hit home.'' Local municipal records include birth and death certificates, deeds, land transfers and tax lists. ''Out of disaster comes benefits,'' Mr. Persempere said. ''We need alarm systems, early warning systems that can save the records. That's my baby.''