FOR MOST PEOPLE the census is over. In theory, anyway, the forms arrived last week, were promptly filled out and dropped back into the mail as April began. But, especially for people who got the long form, the memory will linger on, if in fact an uncompleted form is not lingering on as well. It is not a pleasant memory, and the Census Bureau should reflect on this before it plans its next exercise in extracting information.

It is easy to understand why the statisticians, policy planners and business researchers want the answers to all those questions; but it is just as easy to resent the obligation to provide them. Really now, should Americans be required by federal law to tell the government how many bedrooms they have, whether their living quarters are air-conditioned, what their ancestry is?

The decennial census has grown too big. Despite efforts by the Census Bureau to keep down the number of questions -- it rejected proposals that it also ask about, among other things, home swimming pools and insulation -- the census form is taking on the aspect and heft of the income tax form. One look at that long census form last weekend, and some people must have been tempted to run down to the shopping center in search of paid help in filling it out.

The Census Bureau may be on the verge of squandering the citizen cooperation on which its success rests. While there was 10 years ago -- thanks largely to the efforts of minority organizations to make sure everyone is counted -- the antagonism is just below the surface.

Maybe the bureau should go back to basics -- name sex, age and a few other such details. That would speed up the process, probably produce a more complete result and fulfill the basic mission of the census -- creating the numbers on which seats in the House of Representatives are allocated.

If any of the wealth of other information being sought this year is vital to the successful operation of government, it could be collected at another time on a sampling basis. (Most of it is being collected on that basis now.) As for the rest of the information -- what difference can it possibly make to the govrnment whether your first marriage ended in the death of your spouse? -- collection should be left to the industries or organizations that are its principal users and beneficiaries.