OLD JOKE: The three biggest lies in the world are "The check is in the mail," "I have a headache," and "I'm doing this for your own good." But there is another that should rank much higher.

The greatest lie of our times is poster gum.

We all know it, and many of us say it, but few of us have had the courage to combat the massive disinformation campaign that began to confront us when we were innocent little froshlings entering the Yard for the first time. Poster gum, we were told, magically allows us to decorate our rooms without destroying the (ahem) priceless architectural treasures we inhabit. (I apologize to Mather House residents for excluding them from the discourse. Try to think back to your first year, and maybe something will ring a bell. If you lived in Canaday, I can't help you.)

THE SAD TRUTH, however, is that poster gum simply does not work. Yesterday, I went to the Quad for a two-hour tutorial. When I left, my bedroom walls featured a typical smattering of undergraduate decor--pictures of friends, a Van Gogh print, my favorite Far Side and New Yorker cartoons, Martin Luther King, Jr., and David Ben-Gurion matching visionary stares and so on. When I returned, the collection was unceremoniously gathered on my floor.

It was most difficult to try to rear-range my spatial orientation by 90 degrees. I tried sleeping on the wall to reproduce the original pattern, but I couldn't seem to stay there, no matter how much poster gum I used.

Someone will now pipe up with some inanity like, "That's because you used too much poster gum. Just use a little, and use it well," I may have believed it as a rookie back when my posters fell off the wall in Matthews, but the view is different from Leverett House.

There is no such thing as a better way to use poster gum. I tried putting it just on the corners of my posters, or just on the middle of the top side, or dead center after boiling a live cat and dancing a Highland fling, but nothing works. Sure, they stay up for a while, but we all know how it ends. In the middle of the night, each of us can expect to dream that the sky is falling. Chicken Little didn't know how good he had it.

Neither, for that matter, did Sisyphus. I am convinced that when I die, the gods will put me in a never-ending Harvard dorm room with an infinite number of posters, and I will spend eternity trying to keep them all up on the wall at the same time. Futility of futilities.

IMAGINE HOW FOOLISH major historical events would seem had previous generations been made to use the same glorified silly putty that is forced upon us. Martin Luther gumming his 95 Theses to the door of Wittenburg Church just doesn't resonate with theological thunder. Nebuchadnezzer's Hanging Gardens of Babylon wouldn't have stayed up had he trusted the gum. And the ancient Romans would have been hard pressed to devise a method of execution that used poster gum instead of nails, unless they had been diabolical enough to realize that protracted attempts to use the stuff can themselves weaken the will to live.

Why we should retreat from earlier, more glorious methods of affixion is unclear, and Harvard students, being clever folk, have devised several ways to circumvent the problem. One favorite is to place a dab or two of poster gum around the edges of the poster, in order to give the impression that all is in accordance with College regulations, and then liberally apply masking tape closer to the middle of the poster.

But others are not nearly so tame. One student, who spoke under the twin conditions of absolute anonymity and the gift of a large hammer, acknowledged over lunch that he pounds posters into the walls with as many staplers as he can find. "You'll never get me to believe that Bok uses poster gum in his office," he said. "The whole thing is a big joke the maintenance staff lays on us, year after year. Well, I'll show them."

With that, he glanced nervously about him, produced a stapler from his backpack, and forcefully united his Chick-wich and the underside of the dining hall table. It may still be there.

CLEARLY, such extreme reactions signal the intense psychological strain that so many of us suffer from always returning to our rooms unsure of the extent of gravitational damage. We all know that poster gum is defective; anyone who tells you otherwise is either an unwitting dupe or a paid agent of the faceless forces behind the ongoing Teflon conspiracy.

Some sources say the identities of the ringleaders are known, but they have not made the charges stick. Eventually, however, we will find them. They could hang, although we can't say with what.

But one thing we can promise: When the revolution comes, they'll be the first ones against the wall.