SO YOU STEP OUTSIDE on midnight, Dec. 31, 1999, to welcome in the New Year and the new century and all the lights go out. Your bank account is wiped out, your flight to Cleveland is diverted to Rwanda and a notice arrives saying, bring your horse, you've just been drafted into the U.S. Cavalry.

All of this happens because the computer geniuses who have been held up to the rest of us as the wave of the future were taken by surprise by the future. Much software is programmed with only two-digit dates for the year, 98 for 1998, 99 for 1999, but when we get to 2000, the computer will think it's 1900.Or so I've read. I don't know whether any of this is true, but I'm easily convinced that any problem is far worse than previously thought.

This problem even has a name, Y2K, for year 2000, a name popularized by Vice President Al Gore and the metric cabal who want us to believe that K stands for 1,000 instead of its true meaning, strike out.

And the cause of the problem goes by the Michael Crichtonlike name of "the millennium bug," which plays into popular doomsday fears that if something big like an asteroid doesn't get us first, something tiny like a virus will.

Faced with the possibility that tens of millions of Social Security checks may all be mailed to the same grain and feed store in Dimmit, Texas, President Clinton has joined Gore in the Y2K fracas. The administration says Y2K is one of the greatest technological challenges in history. In a century that has seen the automobile, airplane, television and men on the moon, the greatest challenge is a programming glitch?

The problem exists everywhere there are computers, but we Americans have already put our own peculiar spin on it. Companies are afraid to share tips for fixing Y2K problems because they're afraid of being sued - and with reason: Preparing to sue the chips off companies that have millennial computer problems is described as "a burgeoning legal specialty."

The problem also has a neat little international angle. After we goaded and prodded all these Third World countries into buying computers - thus putting out of work all the people who worked the manual calculators and sorted the 3x5 cards - we have to tell them the stuff we sold them for millions of dollars won't work after next year. Nothing like a good laugh at the expense of the developing nations.

Maybe the Y2K alarmists will be wrong, that banks, hospitals, reservation systems, air traffic control, credit card billing, assembly lines and power grids won't go haywire. If so, I want the alarmists dragged onto a reality-based TV show called "Shame!" where, in a rite akin to an Iron Curtain show trial, they are forced to grovel and apologize and explain how they could be so laughably wrong. If the alarmists are right, you can bet they'll waste no time telling us about it.

If they are right, not all is lost. The Clinton administration and the Newt Gingrich Republicans have gushed on and on about access to the Internet and giving every kid a computer.

By the time every kid gets a computer it will be the year 2000 and the stupid thing won't work. The combination of flawed technology and failed government promises will put the necessary steel in their souls to face the challenges of the 21st century or, if it comes to that, the rerun of the 20th century.