Every seven years, whether you need it or not, you ought to take a real vacation -- one where you completely escape the constraints of your workaday world. For three weeks in April, I was lost to that world, wandering among the beaches and markets, the flowered hills and twisting mountain roads, the ancient temples and museums of Greece.

On returning, I discovered that I had missed three signal events: the successful and gripping flight of Columbia, the first American space shuttle; my paper's, The Washington Post's, misfortune with our Pulitzer Prize fiasco; and President Reagan's triumphant speech to the joint session of Congress, marking his return to the political wars after the attempt on his life.

Largely as a result of these three events, the returning vacationer finds a significant alteration in the atmosphere of this capital city. It has become Ronald Reagan's town in a way it was not at the beginning of April. When I left, he was the untested president the people had chosen and an attempted assassin had almost removed. When I came back, he was a leader whose primacy -- at least for now -- is acknowledged by every decisive element in this city's power structure.

That Reagan himself spent most of his April days recuperating from his gunshot wound and surgery does not diminish the change in his status. Rather, the change is all the more impressive just because it seemed so unpremeditated on his part. The effect is to persuade people that larger forces are propelling him into a historic position.

As was predictable, Reagan's narrow escape from death and his cheerful acceptance of the pain of surgery gave a mythic dimension to his affable personality that had not been there before. The shooting almost immunized him from personal criticism.

In mid-April, the space shuttle bolstered him further, even though objectively he contributed nothing to the design or execution of the project. Like his inauguration day and the return of the hostages and the aftermath of the shooting, it was a widely watched television event that brought Americans to a common consciousness of their mutual pride. It was a triumph for technology, strengthening the fundamental Reagan assertion that American know-how and effort are sufficient to overcome whatever challenges face this nation. It was a success story, important psychologically for an administration whose whole economic program rests on the belief that positive thinking can produce positive results.

As for the humiliation The Post suffered in the blowup of the "Jimmy's World" story, it is hard for me to be objective about the institution that has been the center of my working life for 15 years. But objectivity is demanded, because The Post plays an important part in shaping the climate of Washington decision-making.

Since 1966, when the Vietnam War issue broke The Post's intimate relationship with the Kennedy-Johnson administrations, the paper has been seen in Washington as the scourge of successive presidents, both Democratic and Republican. As such, its pages have become a rallying-point for whatever is the current political opposition.

Without suggesting for a moment that The Post will now pull its punches in reporting or editorial comment -- for it will not -- it is evident in coming back to the paper, that we are in for a prolonged period of introspection and self-examination. Like the Republican Party after 1964 and 1974, like the Democratic Party after 1980, we at The Post recognize that our long-term health requires that we take some of our time and energy to reexamine our own values, assumptions and actions. And during that time, Reagan may enjoy a respite his predecessor presidents may have envied.

The final event -- last week's "return of Reagan" speech -- is one for which he can claim full credit. Walking around Capitol Hill a few days after the speech was like walking into a village a few days after an earthquake has hit.

Even if you missed the moment when the earth moved, you knew something powerful had happened. "That guy," one Kennedy Democrat in the House remarked of Reagan, "is damned formidable. Even the Democrats back home want him to succeed."

How long this will last is uncertain. The Greek myths I have been reliving the last few weeks are full of lessons of the danger of hubris -- of excessive pride. But for now, Reagan rides high.