Singled out to re-experience what the whole country went through in the 1973-74 gasoline shortage, many Californians stress an important difference: The earlier shortage had an identifiable cause-the embargo imposed by the Organization of Petroleum Exporting Countries.

But despite much cynical comment no one has any plausible explanation for the origin of this state's suddenly developed gasoline shortage. Nor is there appreciation for President Carter's observation that California's plight will at last make the country realize that it has a serious energy problem.

Overdependence on the vital liquid-gasoline-is an acquired taste that perhaps doesn't merit lavish sympathy, but in this overmotorized state, the sense of being played around with by unseen forces has achieved a common acceptance that was not present the last time around.

Many explanations are offered for the return of long lines at California's filling stations-with their accompanying tales of personal and business disruptions, occasional violence as tempers exeed control and the usual gush of marginally useful advice about conserving gasoline: Try to combine a number of errands, make sure tires are properly inflated and so forth.

One of the first explanations was that the shortage could be traced to the state's April gasoline allotment being overwhelmed by the peculiarity of five weekends in that month. But California was not alone in having a five-weekend April this year; it is the only state, however, that experienced a serious shortage, and the shortage is continuing into this month.

The next explanation was that the Department of Energy made a simple arithmetical error in calculating California's springtime gasoline needs. It seems, according to that particular analysis, that the DOE neglected to take into account the growth of motoring in the state and instead, based California's allotment on the old numbers.That's one of those if-you-believe-that-you'll-believe-anything explanations, and it has not gone down well.

Iran and the cutoff of the 5 percent of imports that it contributed to the United States is often invoked, but apart from the fact that California is the only victim of this negligible reduction, there is also a glut of Alaskan oil that passes through this state for reshipment to the East. Refining capacity is said to be a big problem but, again, why should California be the only loser?

Still another explanation is that California's supply is quite sufficient, but panic buying-reflected in an urge to keep tanks full-has eliminated the small margin of surplus that keeps the gasoline supply system flexible and seemingly plentiful. There may be something to this but, again, Californians are asking-without getting any satisfactory answer-why this problem has had acute consequences only in their state.

Gov. Jerry Brown has responded to the shortage by giving the counties a local option for reinstituting odd- and even-day sales based on license-plate numbers. He has also recommended that "topping-off" sales be prohibited by requiring that purchasers have less than half a tank full; also that no sales may exceed 20 gallons. But, as Brown notes, these arrangements concern only distribution, not supply. And without an increase in supply, the overall effect will be no more than a slight reduction in incovenience.

What is most striking about the public response to this shortage-among physics professors, hotel clerks, fellow motorists in gas lines and among many other people one encounters-is the rampant disbelief that it has evoked. How, if at all, this translates into a political response, is not certain but not often have so many people unanimously felt that they are the victim of some irrational force-and, furthermore, that their political leaders simply don't care.