What was going on when I was born?

Israel is now engaged in some sober arithmetic, adding up the pluses and minuses of its intensive bombing of Lebanon, including Beirut, and of the cease-fire that halted the fighting on Friday. The ledger shows significant gains for Israeli interests, militarily and politically. But the losses, from the Israeli perspective, are equally dramatic, including the diplomatic damage to Israel's reputation and the enhanced status of the Palestine Liberation Organization. The military gains include losses inflicted on the new, heavy artillery and multiple-rocket-launchers that had recently been acquired by Palestinian guerrilla units in Lebanon and moved south to within range of Israeli border towns.

that is, vitamins - even the washroom graffiti reads, ''Take your salt and sportsmins.'' Outside, the playing field - enclosed by a high stake fence to keep some practices secret - was vacant now, except for a lone player. He was making several slow, almost lumbering laps around the field; his black curly hair glistened with sweat under the warm California sun, the sun that had bleached the tan mountains behind him. This was Jim Plunkett, the 33-year-old quarterback who was beginning his 12th season in the National Football League. Down on his luck at the beginning of last season - no team had any interest in the veteran, except Oakland - he took over as starting quarterback when Dan Pastorini, the first-string quarterback, suffered a broken leg in the fifth game; then in storybook style Plunkett, the son of blind parents of Mexican-American ancestry who grew up poor in the nearby San Jose barrio, led what was a struggling Raider team all the way to a Super Bowl victory. He was named the most valuable player in the game.

They started, most of them, in Georgia in the spring and they have moved north with the warm weather. Once they were a rarity, sometimes only one a year, but their numbers have increased sharply. They are the hikers who are out to go the entire distance of the Appalachian Trail and many of them are now passing through the New York, New Jersey and Connecticut sections of the trail on the way to its end at Mount Katahdin in Maine. From its beginning in Springer Mountain in Georgia, the trail extends 2,050 miles in 14 states, running along mountain ridges and through forests - and often, because of recent of land development, along paved roads. ''It's like a whole different world strung out along the trail,'' said 24-year-old John Jurczynski, who started hiking on the trail on March 29. ''It's like a moving community.''

From the architecturally innovative pedestrian mall that has revitalized the downtown business area to the newly restored residential neighborhoods bordering the commercial district, Minneapolis is a company town, a thriving urban center where virtually every civic improvement has been planned and paid for by the prosperous corporations that have their headquarters here. ''The most important things in this city have happened at the initiative of the business community, not because of government,'' Mayor Donald M. Fraser says. As cities around the country face cutbacks in Federal aid for housing, welfare and the arts, Minneapolis and neighboring St. Paul are suddenly the focus of national attention because so much has been accomplished with so little money from government. Urban experts are flocking here to study the ''Minnesota model'' for developing business-government partnerships to tackle community needs. Several cities already have organizations that are based on one in Minneapolis that gets corporations to pledge a percentage of their pretax profits to civic projects and charity. Another Minneapolis-based organization has initiated enterprises in several depressed urban communities around the nation.

Caught in a profit squeeze as the result of high interest rates, the nation's 15 largest banking concerns experienced a difficult second quarter. Nine announced earnings declines from the levels of the second quarter of 1980, and 12 reported declines in their annual rates of return on total average assets, which indicates their basic profitability. The main problem was a shrinkage of the difference between the average rate banks paid for their funds and the average yield on their loans and investments. This, they said, reflected the unexpected persistence of high interest rates.

The Palestinian guerrilla leadership today sharply criticized a radical faction that has refused to honor the shaky cease-fire along the Israeli border in southern Lebanon. In a statement read over the Voice of Palestine radio station and distributed by Wafa, the Palestinian news agency, the Popular Front for the Liberation of Palestine-General Command was termed ''irresponsible'' and ''heedless of Lebanese and Palestinian blood.'' The unusual public rebuke from the guerrilla leadership emphasized the delicate nature of the cease-fire, which can be broken by any of a number of volatile, heavily armed forces. The guns were silent today along the border area of rugged hills and narrow, terraced valleys, which have echoed with the sound of artillery and rocket fire for the last two weeks.

Renaldo (Skeets) Nehemiah's immediate goals are faster times in the 110-meter high hurdles. But looking toward the 1984 Los Angeles Olympics, Nehemiah and his new coach, Wilbur Ross, have set their sights on a more ambitious gold-medal plan - the hurdles and the decathlon. Nehemiah confirmed his long-range intentions today after outrunning Greg Foster and six other rivals at the National Sports Festival with a wind-aided time of 13 seconds. Considering the unfavorable conditions - rain, a soft, spongy track and Nehemiah's uncertain status after an injury earlier this year - it was an astonishing performance. Nehemiah holds the world record at 13 seconds and ran a wind-aided 12.91 two years ago.

At 4:57 P.M., Wes Campbell, a driller working for the Shell Oil Company, lowered a column of steel pipe deep into the Atlantic, 200 miles off the coast of Massachusetts. The drilling column stiffened slightly as it hit bottom and then punched a 17 1/2-inch hole in the sandy face of Georges Bank. Fifty miles to the west, the Exxon Corporation sent its drill bit spiraling into the layers of sedimentary rock in search of oil and gas. After six years of bitter legal wrangles between fishermen and oil companies, exploration began today on Georges Bank - one of America's richest fisheries.Zapata Saratoga rig were a knot of Shell Oil officials, nine journalists and a group of curious finback whales who poked their heads through the distant waves, sending up fountains of spray.

City and state officials said yesterday they had tentatively agreed to a plan that, if remaining details were worked out, could clear the way for construction of the Westway highway project. The officials said they had agreed that, should the Federal Government not provide all the money that is needed for the Westway, they would then ask the State Legislature to create a bonding authority that would try to raise the necessary funds. If the Legislature refused to agree to such an authority, the officials said, Governor Carey was prepared to join with Mayor Koch in seeking a trade-in of available Federal dollars for construction of a more modest roadway and for mass transit. The officials also warned, however, that uncertainties remained before a deal could be finally struck. These center on critical questions of timing and on the fact that key decisions would have to be made by the State Legislature and the Federal Government - whose actions cannot be forecast.

International Palestinian guerrilla leaders censured a radical guerrilla faction that has refused to honor the shaky cease-fire along the Israeli border in southern Lebanon. The Popular Front for the Liberation of Palestine-General Command was described in a broadcast statement by the Voice of Palestine radio as ''irresponsible'' and ''heedless of Lebanese and Palestinian blood.'' Except for three brief incidents of firing by the defiant faction, the cease-fire has not been violated. (Page A1, Column 6.) Philip C. Habib arrived in Washington and was expected to discuss with President Reagan and Secretary of State Alexander M. Haig Jr. the cease-fire he helped negotiate as the United States special envoy to the Middle East. Meanwhile, Senator Henry M. Jackson, senior Democratic member of the Armed Services Committee, said there was no question that the United States would resume delivery of the F-16 planes to Israel. (A6:3-6.)

President Reagan is preparing a final effort to get his tax bill through Congress. Yesterday he entertained 15 Democratic Representatives at Camp David, and tonight he will address the nation on television. However the TV address, on the advice of Republican leaders in Congress, will make no mention of proposed cuts in Social Security benefits. (Page D1.)

From his house on the bluff, the warden in years past could see sailboats fluttering along the broad Hudson River and, across the iridescent water, the Palisades cliffs. To this day it is a priceless view, even when interrupted by the cross-hatched metal bars and the broken window panes of Cellblock B at the prison here once known as Sing Sing. The shattered vista is best from the fifth tier of stacked cells facing a mammoth window that reaches from the concrete floor to the ceiling. A precious piece of that view belongs now to the Village of Ossining, which has just received 10 acres of what was known as the warden's property from the state for $1. The prison is now run by a superintendent instead of a warden.