I am therefore amazed that, despite our vast collective social experience, many benighted individuals seem to have trouble digesting the general concept of the door. Why is there a sorry segment of the population that doesn't understand proper door etiquette? There is an etiquette behind doors -- a set of Door Rules that, though unwritten, has governed door operations since days of yore.

Most people understand and obey the Door Rules unconsciously, becoming aware of them only when they are broken. The rules are broken, of course, on a daily basis -- usually by the cross-eyed, the oblivious, and the insane. As it happens, I have found that there are more rule-breakers in Boston, and at MIT, than anywhere else in civilization.

Breakers are most dangerous when they attack en masse, as at the Park Street T station, which is the bloodiest battlefield in Boston. Whenever a trolley arrives, hordes of waiting passengers cluster around the car doors, preventing riders from disemtrolleying. This blatant violation of Door Rules is made worse by the flanking maneuvers often undertaken by the worst offenders, who flutter on the periphery, endeavoring to block any and all rider escape routes. Alighting riders counterattack -- jabbing elbows, swinging packages and catapulting young children -- and the whole situation degenerates rapidly and senselessly.

It doesn't have to be this way. If only the people on the platform would remember the Door Rules! There is only one principal T-related Rule -- to let people off the train before trying to board it yourself. In New York, of all places, people are better at this, and not because of any Giuliani-induced politeness crusade. For some reason, New Yorkers understand the value of letting people off the train before attempting to board. Does following the Door Rules imply businesslike effiency, or just plain common sense?

I might be persuaded to forgive Bostonians for breaking the Door Rules; in fairness, I'm not from around here, and I don't understand the local customs that might be involved. After all, Boston is a frightening place where both streets and drivers wander drunkenly and direction is often meaningless. Approaching a Boston corner, and don't know if you should turn left or right? Straddle the left two lanes and turn on your right blinker! (I digress.)

However, I expect MIT people to be better about the Door Rules. I am sadly and maddeningly disappointed time and time again, though, even in T stations, where I often notice MIT faces among those clamoring to get on the train as soon as it arrives. In fact, I could swear, although I'm not sure, that I once saw President Charles M. Vest himself in such an inexplicable fever to board a trolley at Government Center that he hurled to the ground an old woman who was trying to disembark.

My frustration with MIT rule-breakers is actually greatest on campus, at three locations in particular: the door to Walker Memorial, the Building 8 entrance to the Infinite Corridor, and the two rows of doors leading into the Student Center. At all these places, I frequently find myself straining to avoid striking people who, busy in La-La Land, can't be bothered to use the doors intelligently.

If I'm lucky, it happens to me only a few times a day: I'm approaching a set of doors -- two doors, one on the left and one on the right. There is a person several paces ahead of me who reaches for the door on the right, opens it, and goes through. He may even hold the door open for me. But just as I am about to enter, some yo-yo heading the other way exits through the open door -- wrong, since the open door is on the exiting person's left! As I stop suddenly, to avoid hitting the yo-yo, I scream mentally, "Use the door on the right, doofus!"

Why can't we just all remember to use the door on the right? Don't use the door on the left, even if it happens to be open. Even if using the left door wouldn't put you in anyone's way, you still shouldn't use the left door. (Remember, it's illegal to run a red light, even if nobody's around for miles.) Follow the Door Rules. Walk on the right, and use the door on the right. Don't try to slip through on the left, even when nobody else is around, because the entire door system will break down. This is MIT; we don't need any more systems breaking down.

Oh -- and don't trample little old ladies trying to get off the T.