What was going on when I was born?

The houses and fishing shacks are daubed mint green, dandelion yellow, lobster pink and a palette of other hues. The church steeples are blindingly white, like the freshly laundered sheets flapping on the lines. The beaches come in two colors, white and red; the red, they say, makes better sand castles. Prince Edward Island, Canada's smallest province, is a vacationland by Technicolor, a panorama of wholesomeness that might make Disneyland seem risque. There is, in fact, a fairy-tale aura about this crescent-shaped island - 140 miles from tip to tip and in some places no more than four miles wide - curled off Nova Scotia and New Brunswick. Was this once a big island that some enchantress shrunk? Or is it a scale model that got out of hand?

The United Mine Workers and the bituminous coal industry signed a new contract here tonight that will put miners back on the job at 12:01 A.M. Monday after a 73-day strike. The 10:30 P.M. ceremony in the lobby of the union's headquarters came after a day of balloting in which the 160,000 union members voted overwhelmingly to ratify the 40-month pact. Sam M. Church Jr., the U.M.W. president, said late tonight that with the votes of only a few small locals remaining to be counted, the contract had gained nearly 70 percent approval, with 57,210 for ratification to 25,798 against, the largest ratification margin in the union's history. The contract was the second offered by negotiators of the union and the Bituminous Coal Operators Association, the bargaining arm of the major Eastern and Middle Western mining companies.

Ronald Reagan, the darling of the business community, has given business its first great surprise. The man who has delighted a generation of businessmen with his free-enterprise ideology has offered his tax compromise to conservative, deficit-conscious Democrats, and it comes largely and unexpectedly at the expense of business. Mr. Reagan has tailored a compromise that, to all appearances, favors supply-side fundamentalism - the sweeping, three-year, acrossthe-board tax cuts known as 10-10-10 - over supply-side theology - the more narrowly focused, greatly liberalized tax depreciation plan that business knows as 10-5-3. The new plan essentially stands by Mr. Reagan's sweeping, threeyear tax cuts and then pays for that stance with concessions on business taxes. Though undoubtedly the President espouses both approaches, his compromise favors the philosophy that the supplyside miracle - and political mileage - lies more in the dramatic, successive tax cuts for individuals than in more methodical tax relief for productive industry.

WASHINGTON AFTER the Rose Garden announcement of President Reagan's hastily revised tax-cut legislation, a reporter asked the President if he had the votes in Congress to pass the measure. ''I said we wouldn't take any questions, and I'm glad I said it,'' Mr. Reagan quipped in his amiable way as he headed back toward the Oval Office. In an aside to an aide, he was heard to murmur that no one ''really knows the answer to that question.'' The President's retreat from further inquiries was understandable. It came at the end of two weeks of the most intricate and confusing political maneuvering seen so far in the new Administration. The questions that hung in the air at week's end were tough ones, indeed.

It has been called ''the abstract Woodstock,'' ''the rich man's Provincetown,'' even ''the cradle of American art,'' and there is a certain truth to each of these epithets, for the last few decades have seen the avatars of the avant-garde as well as some of the foremost practitioners of landscape painting settle on that narrow strip of land known as the South Fork or East End of Long Island. There, amid the dunes and wastes of scrub oak, such artists as Willem de Kooning, the late Jackson Pollock, Lee Krasner, James Brooks, Adolph Gottlieb, Franz Kline, Roy Lichtenstein, Alfonso Ossorio, Larry Rivers and James Rosenquist made their homes and built their studios, and it was there that they helped redefine American - and 20th-century - art. Such a community of talent, of course, is wonderfully uncommon, and over the past half century, Guild Hall, East Hampton's center for the visual and performing arts, has done its best to show the work of these resident artists and others. Beginning this Wednesday, some of their finest paintings and sculptures will be on view at the Knoedler Gallery, in a special exhibition arranged as a ''salute'' to Guild Hall from New York's four major museums - the Guggenheim, the Metropolitan, the Modern and the Whitney - all of which have loaned pieces from their own collections.

Housing availability and the presence of a labor market are becoming increasingly important criteria when corporations select suburban office locations, according to developers and real estate brokers. They overshadow such factors as transportation access, design quality or rents. The specialists reported other characteristics of a changing suburban market, a market that is benefiting both from internal growth and some move-outs from Manhattan: * Competition has kept rent increases relatively modest, but the rising cost of construction is leading builders to predict much higher rents for new construction. * Although some downtowns, such as Newark and Morristown, N.J., and White Plains, N.Y., and Hartford, Conn., are strengthening, ''suburban sprawl'' is increasing as new office construction moves to locations more distant from the chief urban centers. * Suburban office projects are growing larger and tending increasingly to mixed use, with hotels, conference centers, retail and even residential facilities included.

ONCE again Nassau County is turning to the state in an effort to resolve the controversy over crowded conditions in the County Jail at East Meadow. The overcrowding, which has existed for several months, has led to tension-filled situations among prisoners as well as lawsuits and court clashes. A legal and governmental confrontation was precipitated recently when Federal Judge George C. Pratt ordered the county to release 15 prisoners for every 14 admitted to the jail until the jail population had been reduced to 517, the number fixed by the State Correction Commission, based on cells and space available. The number of inmates in recent weeks has been hovering near 700 after 175 were put on work-release programs or were hospitalized and 100 were sent to the Erie County Jail to help relieve the situation. Erie charges Nassau $5,000 a day for the group.

Two housing developers, one a former public official, are embroiled in a dispute involving their purchase of a warehouse building bordering New York City's convention center project. Harold L. Fisher, a former director of the Convention Center Development Corporation, has questioned whether the developers might have had access to any inside information before buying the 11-story building at 11th Avenue and 35th Street from the Penn Central Corporation for $345,000 in 1979. Subsequently, the state Urban Development Corporation took the building by condemnation to clear the way for a plaza for the convention center, and received and rejected the developers' claim of $1.3 million for the property. The developers, Jerome Kretchmer, a former city environmental protection administrator, State Assemblyman and State Senate counsel, and Austin Laber, a real estate lawyer, ridicule and deny suggestions by Mr. Fisher and others that they were ''trying to pull something off on them,'' in Mr. Kretchmer's words.

Considering the volatile combination of 21 candidates, nearly as many media consultants, $6 million in state campaign funds and an electorate that was thought to be too weary or too confused to show an interest, the result of last week's gubernatorial primaries in New Jersey was something of a surprise. The favorites won. Republican Thomas H. Kean, a former assemblyman who advocates a package of spending cuts and reductions in the state's payroll, sales and corporate taxes modeled on the supply-side tenets of the Reagan Administration, drew 31 percent of the vote. He was followed by Mayor Lawrence F. Kramer of Paterson, with 21 percent, and Joseph A. (Bo) Sullivan, a businessman who refused public funds and spent about $2 million of his own on the campaign, with 17 percent.

The Reagan Administration has begun to feel the first resistance to its ambitious plans for national defense as Congress prepares to debate proposals for a new fleet of bombers, the MX intercontinental missile and the large sums to be appropriated for the 1982 military budget. ''There are serious warning flags being raised,'' said Senator John C. Stennis of Mississippi, who is widely considered to be a steady advocate of military strength, in a recent Senate speech. The senior Democrat on the Armed Services Committee contended that if the Federal budget continued to show a deficit, ''there will be great pressure to restrain the defense budget.'' Conversations with a variety of current and former military officials, specialists in research organizations, scholars and Congressional officials suggest that the initial enthusiasm for immediate increases in military spending has started to fade.

IF New York State's 21,000 physicians are required to pay the proposed increases in malpractice insurance premiums ranging from 71 percent to 367.8 percent, the impact will be felt significantly on the Island, where doctors will pay the highest rates in the state and very likely will pass some of the costs along to their patients. Doctors in three counties, Nassau, Suffolk and Sullivan, in the Catskills, are charged the highest premiums for liability insurance against a possible suit for alleged malpractice. A spokesman for the Medical Liability Mutual Insurance Company, the largest insurer, said the rates were determined by multiplying the total number of claims filed against physicians by the average payment in the lawsuits. The Medical Liability Mutual Insurance Company has 1,509 policy holders in Nassau County and 1,121 in Suffolk. Insurance officials say the request for higher premiums, which would go into effect July 1, does not reflect on the quality of medical care on the Island, but rather might be attributed to the fact that more physicians here practice high-risk specialties. Moreover, they say, the physicians are treating more patients who are litigious, spurred on by publicity concerning large settlements.

The flame under the five-week-old crisis over Syrian missiles in Lebanon flickered a bit lower last week. Prime Minister Menachem Begin boasted that Israel could ''destroy those missiles in two hours,'' but after meeting with Egyptian President Anwar el-Sadat, he agreed to allow more time for diplomatic efforts.