What was going on when I was born?

The nation's two largest banks yesterday reported their earnings for the third quarter, conveying two sharply contrasting reactions to falling interest rates. The BankAmerica Corporation, the nation's largest bank holding company, reported that its operating income fell 13.7 percent, to $103 million, or 70 cents a share, compared with $119.3 million, or 81 cents a share, for the same period a year ago. Citicorp, the nation's second-largest bank holding company, said operating income in the third quarter increased 55.6 percent, to $210 million, or $1.61 a share, from $135 million, or $1.07 a share, in the same period last year. While Citicorp and other leading banks benefited significantly from declining interest rates, BankAmerica's net interest income rose only 2.8 percent in the quarter, to $733 million, compared with $713 million in last year's quarter. The net interest margin - the spread between the bank's cost of funds or deposits and what it earns on loans - fell to 3 percent, from 3.1 percent in the 1981 period.

The Education column in Science Times yesterday gave two incorrect figures for California high school seniors' Scholastic Aptitude Test scores. From 1972 to 1980, scores on the mathematics section dropped an average of 21 points. The average on the math section this year was 474.

THE first image conjured up by the word ''bread'' is that of a sliceable loaf, its shape a matter of custom and ethnic preference. Americans tend to think of all breads as baked in ovens - oblong loaves, flat breads, round loaves, crusty ovals or sticks of baked dough almost as sturdy as baseball bats. Baking, so goes the conventional wisdom, means cooking in ovens. The fact is, baking means cooking by dry heat. For thousands of years cooks have been turning out bread in whatever way is convenient to their mode of living, by a process that may take place in an oven or on a heated surface of stone or iron. Such cooking may result in risen loaves to be cut with a knife or in pliant cakes as flat and accommodating as a tortilla. There is considerable sport in turning out your own breads at any season of the year, and there is little doubt that many good cooks choose the cooler months to ply the gentle art of baking. Among the more obvious advantages of loaves baked without the aid of the usual oven - say, on a crisp October day - is the ease with which such breads can be made. To some beginners the whole act seems simpler.

Unheralded, arriving in a squadron of sleek corporate jets, 21 senior executives of several of the biggest corporations in the United States arrived here today for private talks with Prime Minister Pierre Elliott Trudeau and his Cabinet about the investment climate here. The unusual gathering, which included top officers of six major oil companies, was to have been held in secrecy, An official of the Canadian Ministry of External Affairs, who helped coordinate the meeting, said the executives agreed to come only after the Niagara Institute, a business-sponsored research group that is the official host for the meeting, agreed to protect their identities. But the sense of something unusual in the air was signalled to Ottawa on Monday night, when the first of a daisy chain of American corporate jets began arriving at normally sedate Ottawa International Airport. Even as their passengers were being whisked through customs and downtown to a special 34-suite wing of the green-gabled Chateau Laurier Hotel, where employees were ordered to disclose nothing about their charges, the capital's highly-developed rumor mill was beginning to work.

ARISING tide of inexpensive wine from Europe is rolling across the Atlantic to American consumers in response to sharply expanding demand here, and bargain bottles are showing up in stores all across the country. Not since the early 1970's have such attractive buys from France, Italy, Spain and Portugal, among other countries, been available here, and importers say the situation probably will get even better as time passes. The factors responsible are the strong American dollar and the large supply of wine available from European exporters, who are fearful that the supply will become even greater with the 1982 vintage, which is now being harvested. This year's crop of grapes in Europe may set a record, adding to the downward trend in wine prices. The bargains could not be arriving at a better moment for consumers seeking to stock up for the autumn season of entertaining. It is probable that the wine cost element in the party budget will be the lowest in years or the quality will be the highest - or both.

''There is no alternative than to agree to give parts of the land of Israel away if it will bring peace.