What was going on when I was born?

Chris Evert Lloyd, saying she thought the omens were with her, won her third Wimbledon singles title today, defeating Hana Mandlikova of Czechoslovakia, 6-2, 6-2. Mrs. Lloyd's surprisingly easy victory was achieved in only 60 minutes, before a capacity center-court crowd of 14,000 that included the Duke and Duchess of Kent, Lady Diana Spencer, the fiancee of Prince Charles, and Margaret Thatcher, Britain's Prime Minister. The victory capped a stunningly successful tournament in which Mrs. Lloyd swept all seven of her matches in straight sets, the first such clean slate by a women's singles champion here since Billie Jean King did it in 1967. ''I was determined to win it this year,'' said Mrs. Lloyd, who was runner-up the last three years and who, at 26 years of age, was playing in her seventh final since she first played at the All-England Club in 1972. ''I know when I'm determined I'm still the best,'' Mrs. Lloyd said. ''I proved it at the U.S. Open last year and I proved it here.''

A subway motorman was killed and more than 135 passengers were injured yesterday afternoon when a Manhattan-bound train plowed into the rear of a second train halted for signal trouble in a darkened tunnel in Brooklyn. The motorman, Jesse Cole, a 36-year-old resident of the Bronx who had worked for the Transit Authority for 11 years, was trapped in the twisted wreckage of his cab for four hours after the crash. Authorities said he died about an hour before rescue workers extricated his body shortly before 6 P.M. Passengers told of having seen Mr. Cole through the shattered window of his cab. ''He was groaning and moaning, and saying: 'Help, help, get me out! I'm dying,' '' recalled one witness, Joe Lopez. ''His head was covered with blood,'' Mr. Lopez added. ''We felt so helpless. There was nothing we could do for him.''

Western diplomats here say they are now less pessimistic about the chances of Soviet military intervention in Poland. The assessment came as Andrei A. Gromyko, the Soviet Foreign Minister, flew to Warsaw today for what was described as a ''friendly'' visit. The diplomats' view is reinforced by a notable reduction in the volume and stridency of Soviet press criticism of Poland in recent days, suggesting that the Russians were still some way from the point at which they might decide to intervene militarily or otherwise thwart Poland's push for economic and political changes. Mr. Gromyko's trip was apparently linked to a special gathering of the Polish Communist Party set to open in Warsaw on July 14. Although the policy-making process in the Kremlin remains largely impenetrable, the most credible interpretation of recent pronouncements supports the view that the Soviet leaders are still hoping that the specter of Soviet tanks, coupled with stiff warnings against the unraveling of Communist power, will be enough to uphold essential Soviet interests.

Mayor Koch said yesterday that Governor Carey had ''lost control'' of the mass-transit negotiations in Albany. Mr. Carey, in turn, accused the Mayor of playing politics with New York City subway and bus fares. The remarks, which came in separate telephone interviews, were among the sharpest to date between the two Democratic leaders in what Mr. Koch characterized as ''a growing breach.'' ''He's no longer in command up there,'' the Mayor said of Mr. Carey. ''He was totally unable to deliver a legislative package. He has the worst relations with legislative leaders - the worst.''

The Navy has proposed a vast shipbuilding and aircraft procurement plan that is intended to meet President Reagan's goal of attaining a clear margin of naval superiority over the Soviet Union before the end of this decade. The plan includes two nuclearpowered aircraft carriers, 14 attack submarines and nearly 1,900 airplanes. Senior Pentagon officials said that the program, which seems likely to be approved by the Administration with only minor changes, would require that over five years Congress authorize about $120 billion in spending as measured in 1982 dollars. Some of the actual outlays would come after the five-year period.

The general outlines of the city and state plan for the redevelopment of Times Square and West 42d Street have been known for several months. But they have now moved into a far more definite form -so definite, in fact, that it is possible for the first time to see precisely what the project, should it ever be realized, will look like. What happened was the issuance last week by the New York State Urban Development Corporation, the New York City Department of City Planning and the New York City Public Development Corporation, the co-sponsors of the project, of a formal request for proposals from private real estate developers. Private developers would build the huge project, which is expected to include three or four large office towers clustered around Times Square, an apparel mart and a hotel or residential tower on Eighth Avenue. It also calls for the restoration and conversion to legitimate use of most of the landmark-quality theaters on 42d Street between Seventh and Eighth Avenues.

Otto von Bismarck, the Iron Chancellor of 19th-century Germany, was hardly a New Dealer. But in 1861, in one of several moves to take the wind out of the sails of the socialists, he gave the Prussians the world's first state-run old-age insurance system. Social security has spread since then, and it is causing headaches to governments in many nations, including the Iron Chancellor's land. In 1977 the Bonn Government risked its political life to save the social security system from insolvency. But a combination of factors - longer life expectancy, an oil-induced economic recession, a tradition of openhanded generosity and a court order mandating changes - is expected to further increase the system's cost to West German taxpayers and again threaten its long-term solvency.

The war between Iran and Iraq apparently intensified today, with reports from both sides saying the principal action occurred north of the oil-producing province of Khuzistan.

A single shot fired today at a police car carrying the Rev. Ian Paisley through Belfast missed the Protestant leader, the Royal Ulster Constabulary reported. An anonymous caller telephoned Belfast news organizations and claimed responsibility in the name of the Irish National Liberation Army. Mr. Paisley is a ''legitimate target,'' a statement from the group said. ''I wasn't shocked,'' Mr. Paisley said later. ''I intend to continue with my business as normal.'' Mr. Paisley, who has round-the-clock police protection, was being driven home from an interview at studios of the British Broadcasting Corporation, a police spokesman said.

The Speaker of Iran's Parliament said today that a purge ordered by Ayatollah Ruhollah Khomeini had defeated the opponents of the clergy-dominated Iranian Government. The Speaker, Hojatolislam Hashemi Rafsanjani, made this statement in a sermon at a prayer ceremony at Teheran University a few hours after another anti-Government demonstrator was put to death by a firing squad, this one in the town of Karaj near Teheran. According to official accounts, 90 Iranians, most of them leftists, have been executed since the Ayatollah dismissed Abolhassan Bani-Sadr from the presidency June 22.

China may be forced to resort to ''nonpeaceful methods'' to reunify Taiwan with the mainland if the United States carries out the defense provisions of the Taiwan Relations Act by supplying new weapons, a new Chinese foreign affairs journal has warned. The quarterly journal, Research on International Problems, said in its first issue that advancement or retrogression in relations with the United States depended on the extent to which certain ''upperclass Americans'' carried out the act in violation of American commitments to Peking. ''The provisions in the Taiwan Relations Act, which interfere in the internal affairs of China, can only encourage Taiwanese authorities to reject peaceful talks and oppose peaceful unification,'' said the article, which was approved for publication by senior officials. ''As a result, China may be forced to resort to nonpeaceful methods to settle the Taiwan problem against its wish.''

The Royal Navy, starting next year, will send a squadron built around an aircraft carrier to the Indian and South Atlantic Oceans as a potential reinforcement for American forces in those areas. At the same time, however, Britain will reduce the number of destroyers and frigates assigned to NATO from 59 to what the British Defense Secretary, John Nott, said would be ''about 50.'' The burden of compensating NATO for the nine British surface ships is expected to fall chiefly on the United States at a singularly inopportune moment. For although the Reagan Administration's military budget envisions an expansion of the surface fleet, the ships are unlikely to be available for three more years at the soonest.