What was going on when I was born?

The American Telephone and Telegraph Company reported yesterday that it earned $317 million, or 28 cents a share, in the third quarter, well below analysts' expectations and the forecasts that A.T.& T. itself had made before its breakup in January. The performance was in sharp contrast to the better-than-expected profits reported this week by the seven regional holding companies that were spun off. The last two of those concerns also reported their quarterly results yesterday, with U S West Inc. earning $228.3 million, or $2.39 a share, while the Bell Atlantic Corporation earned $249.5 million, or $2.54 a share. A.T.& T.'s revenues totaled $8.01 billion in the third quarter. Because of the divestiture, mandated in an antitrust settlement with the Justice Department, a comparison of this year's results with last year's is not meaningful. In this year's second quarter, however, the company reported a profit of $456 million, or 43 cents a share, on sales of $8.63 billion.

THURSDAY, OCTOBER 18, 1984 International Strong pressure for lower oil prices was generated by a decision by the British National Oil Corporation to cut the official price of most of its North Sea oil by $1.35 a barrel, to $28.65. (Page A1, Column 4.) The Nobel Prize in Chemistry was awarded to Dr. R. Bruce Merrifield of Rockefeller University for research that has revolutionized the study of proteins and the development of important new drugs. (A1:5.)

The Defense Department is putting the finishing touches on a new military budget that would push its financing up to levels sought earlier but rejected by Congress, Administration officials said today. The officials said the Pentagon was preparing a $333.7 billion military budget for the fiscal year 1986, returning to a figure agreed upon in a long-superseded compromise last March between the Senate and the Administration. The fiscal year 1986 begins Oct. 1, 1985. If approved, the 1986 budget would represent an increase of 13.9 percent over what Congress appropriated for the military in the current fiscal year, which began two and a half weeks ago. This includes an increase to make up for inflation; the increase in real terms would be 8 to 9 percent.

SUNBEAM, Rival, General Electric, Mitsubishi, Electrolux and Juice-O-Mat are hardly the brand names that one would expect to find sitting on a shelf in a Paris shop. But there they are, emblazoned on an impressive array of vintage waffle irons and fans, vacuum cleaners, ice crushers, blenders and toasters from the 40's and 50's at Trophee, a St.-Germain gallery and shop. Trophee is one of a half dozen new home-furnishing shops that top the lists of many Parisians who consider themselves ''branche,'' or plugged in. Furniture from the 1950's as well as today's avant- garde designs, reproduction wine goblets based on a 1920's pat tern as well as sprightly bath towels that look like a Metro ticket are among the things that will appeal to visitors to Paris interested in design and home furnishings. With the exchange rate at more than nine francs to the dollar, small items as well

Construction of new homes, rebounding from two consecutive monthly declines, rose 8.9 percent in September, the Government reported today. The Commerce Department said new housing was started at a seasonally adjusted annual rate of 1.68 million units last month, after declines of 12.3 percent in August and 6.6 percent in July. But applications for new building permits, a sign of future activity, dropped in September for the fourth consecutive month. Permits were taken out at an annual rate of 1.42 million units, down 3.7 percent from the August rate.

''Most alarming are the findings of drug use by youngsters prior to the seventh grade.

Dr. R. Bruce Merrifield of Rockefeller University was awarded the Nobel Prize in Chemistry yesterday for research that revolutionized the study of proteins and is leading to the development of important new drugs. The method he originated in the late 1950's is now used worldwide and has immensely quickened the pace at which research can be done on substances that are indispensable features of all living things. Dr. Merrifield's key accomplishment was a rapid, automated method for making proteins by assembling amino acids, one by one, into chains called peptides. For developing this assembly-line approach, he could be considered the Henry Ford of protein synthesis.

It started with a simple clerical mistake at Mosher, Pooley, Sullivan & Henderson, one of the most successful firms in Silicon Valley's fast-growing legal community. A busy lawyer, making a routine court filing for the National Semiconductor Corporation, neglected to ask the judge to seal a 12-page document. The slip-up was by no means trivial. The document described some of National's most precious trade secrets, the coin-of-the-realm in the cutthroat competition of the Valley. To the horror of James H. Pooley, one of the firm's senior partners, seven of those trade secrets showed up two weeks ago in Microelectronic News, an industry newsletter whose subscribers include every important competitor of National. ''I can only say it was a shock,'' said Mr. Pooley, whose firm has been paid millions by such companies as Tymeshare, Itek and Verbatim to protect their trade secrets.

WHEN many people think of hiring a decorator, they envision a major project in which their entire home will be redesigned, often at substantial cost. But there are those with more modest decorating projects - perhaps just the refreshment of a single room, advice on new slipcover fabrics or a change of an apartment's color scheme - who want to spend less money and time. Customarily, designers make their profits on the trade discounts on merchandise, which they then resell to their clients at list prices. The designer's percentage is a highly variable figure, ranging from around 15 percent to several times higher. A small group of lesser-known design services whose specialty is the smaller project use a different system. They do not expect to order truckloads of custom- made furniture or yards of fine fabrics. Their mandate, for the most part, is to do the best with what a client already owns. They price their services differently as well. Usually the client pays an hourly consultation fee, which ranges from about $100 to $400, depending on the amount of time.

Pleased that she had discovered a spacious Manhattan apartment for a reasonable rent, Eileen Bernstein called home. She told her mother about the large rooms, the space to move about, the fair price. Then she told her about the neighborhood. ''You're living where?'' her mother shouted. ''The Bowery, mom,'' she answered. ''Only it's not as bad as you think.'' To Miss Bernstein's mother, who lives in New Jersey, and her brother, a lawyer who lives on the Upper East Side, the move simply meant that she was crazy. To Miss Bernstein it was a good deal. ''I like to think of myself as business-savvy,'' said the 25-year-old film producer, who shares an apartment on Allen Street just off the Bowery with two friends. ''I like a bargain, and there's no question in my mind that the Bowery will eventually be like the Upper West Side and I'll have gotten in before the rush.''

The four nations that have drafted a peace treaty for Central America said today that they would revise their proposal to meet objections raised at the insistence of the United States. Representatives of the four countries, known as the Contadora group, said at a news conference here that they had not drawn up the revisions. But they said they were optimistic they could satisfy the objections, raised mostly by Honduras and El Salvador, allies of the United States, and by the more neutral Costa Rica. Some privately held out hope for a treaty by the end of the year.

The dollar plunged against major currencies on foreign exchange markets today following intervention by the West German central bank. From its high of about 3.1560 marks early in the Frankfurt trading day, the dollar plunged in what currency dealers described as ''hectic and chaotic'' trading to 3.09 marks. It also fell sharply against the British pound and the Swiss franc, although it remained stable against the French franc. But the dollar firmed later in the day, to 3.1150 marks at the close of European trading, and currency traders, in unconfirmed estimates, said the bank might have sold about $60 million.