What was going on when I was born?

President Reagan's abolition of controls on gasoline is likely to change the way it is sold in the United States, oil industry officials predict. They say the end of price and allocation controls could drive thousands of wholesalers and retailers out of business by making it easier for the more efficient big operators to devour small competitors. In addition, they see some major brands moving out of areas where they were previously common and an accelerating trend toward bigger, less personalized service stations. ''Decontrol has thrown chaos into the situation, and thrown the big oil companies into the driver's seat,'' declared Representative Berkley Bedell, Democrat of Iowa, who has introduced legislation to protect smaller dealers.

President Reagan said today that he had ''no intention'' of involving the United States inextricably in the fighting in El Salvador, but he declared that his Administration would continue to support the Government there against those committed to its ''violent overthrow.'' The President's comments at a brief news conference this morning came as he scheduled a meeting of his top national security advisers tomorrow to discuss ways to bolster El Salvador's Government. El Salvador's military leaders say they can defeat the guerrillas despite a Pentagon report to the contrary, and in interviews in San Salvador they gave a less drastic view of the military threat to the country than the one presented in Washington. (Page A4.)

Underscoring near-record yields prevailing in the fixed-income market, underwriters sold a triple-A debenture issue of the Bell System yesterday at a record return of 14.80 percent. Bear, Stearns & Company, the winner in competitive bidding against two other syndicates, led the group offering a $275 million issue of 40-year debentures for the New Jersey Bell Telephone Company. The successful bid was 98.229 for 14 5/8 percent interest coupons.

A divorced parent's ability to live where he or she chooses may be limited by the right of a child and the other parent to see each other conveniently, the New York State Court of Appeals, the state's highest court, ruled today. In a unanimous decision, the court held that a woman could not move from Westchester County to Las Vegas, Nev., simply to try to make ''a new life'' for herself, because doing so would end the father's ''meaningful access to his son.'' The case involved George David Weiss, a Broadway and movie songwriter, and his former wife, Rosalyn, who said she wanted to move to Las Vegas in the hope of resuming her former career as a singer. The opinion was one of several rulings on family life handed down by the Court of Appeals today. In another, the court gave a narrow interpretation to the circumstances that would justify a court's unsealing the records of an adopted child to disclose the identities of the natural parents.

''THE essential concept to be grasped is the very eminence of chocolate,'' said Milton Zelman, with a far-off look in his eyes. ''It speaks to those who love it. There is something profound about it - but the tragedy is that not enough attention is paid to chocolate.'' Mr. Zelman has been doing his best to remedy that condition, being the proprietor of Chocolate News, a newsletter that, he asserts modestly, ''is chocolate central in the chocolate universe - the clearing house for chocolate information.''

The nation's governors today endorsed President Reagan's proposal to cut the growth in Federal spending, but on the conditions that states be given time to adjust, the poor be protected and tax burdens not be shifted to states and localities. The National Governors Association promised to work with the Administration and Congress on the Federal budget, asserting that ''state governments are prepared to accept the responsibilities of restored federalism.'' A spokesman for Mr. Reagan welcomed the declaration, which, despite its qualifications, could be used before Congress as evidence of support. Larry Speakes, a deputy press secretary to Mr. Reagan, said, ''We appreciate the governors' support and we will continue to seek their advice and counsel.''

Much of what is wrong with American management is most vividly evident in the way a great many companies account for their inventories. That, at least, is the contention of many respected observers of management practices, including Reginald H. Jones, chairman of the General Electric Company, and Peter F. Drucker, the author and consultant. Their indictment springs from what these critics say is the seemingly irrational fondness corporate managements display for the FIFO method of inventory accounting in the current inflationary period. Under FIFO, or the first-in, first-out assumption, reported earnings are higher, but so is taxable income, and therefore, tax payments. Using the alternate method, LIFO, the last-in, first-out assumption, reported earnings are lower, but taxes are, too.

The Supreme Court lowered the legal barrier between the banking and securities industries today by ruling, 6 to 0, that bank holding companies may serve as investment advisers to closed-end investment companies. The decision places banks in direct competition with securities firms and could accelerate the entry of major banks into the investment advisory field, which the securities industry has sought to preserve as its exclusive domain. Bankers interviewed in New York today welcomed the Supreme Court decision but said that the ruling represented for them only a minor wedge into the investment-fund business. ''In practical terms, I don't think there's going to be a flood of banks going into the closed-end investment funds,'' said Anthony C. Howkins, executive vice president of Citibank.

IF you were to canvass any group of serious cooks and ask the name of the one basic ingredient best suited to a no-salt cookery, you would doubtless receive more answers than the components of a Macedonian salad. I would answer without pause: mushrooms. The common cultivated growth has numerous things going for it where low-sodium diets are concerned, most notably depth of flavor and a meat-like consistency. There is, in fact, no vegetable that more closely resembles that of meat. Mushrooms are also low in calories.

Buckingham Palace, giving the British people some news that they have waited years to hear, today announced the engagement of Prince Charles and Lady Diana Spencer, a 19-year-old aristocrat who has been a friend of the royal family all her life. The 32-year-old heir to the throne is to marry in the summer - probably late July - and the wedding is likely to be one of the most glittering royal occasions in years. Lady Diana, the daughter of the eighth Earl Spencer, a wealthy Northamptonshire landowner, has an impeccable social background suitable for someone who may one day be queen. To the delight of many, she is not an idle debutante but rather a hard-working London kindergarten teacher who loves children, avoids nightclubs and stylish parties, and blushes engagingly whenever she is sighted by the posse of press photographers who have been pursuing her for months.

''He met Miss Right and she met Mr. Right. They just clicked.''

An article in Business Day yesterday on AM International Inc. incorrectly stated two of the company's balance sheet items. The company had $104.8 million in long-term debt and stockholder equity of $231.9 million at the end of its 1980 fiscal year.