The Department of Useless Dichotomies has placed the following report.
:: It has come to our realization of late that the people who inhabit this world may be separated into two distinct populations. Of the first can be said this: They are polite, and they demonstrate such by using the phrase "Excuse me" in its intended circumstance: as a signal to people who are occupying the path they wish to travel, that said obstructing people might duly acknowledge the person and shift accordingly, thus allowing the polite person to pass.
More pernicious, though, are the members of the second population. These people, to whom the word "Boor" can be reasonably ascribed, do in fact use the phrase 'Excuse me', but they do not use it as a signal and request. Rather, they utter said phrase while continuing to move at their original rate of speed and along their original trajectory, whether the persons unfortunately in their path have sufficiently shifted to allow passage or not. The meaning of "Excuse me" to the members of the second population, therefore, appears to be a means of self-absolution of any responsibility for collisions that might occur by way of their failure to allow others sufficient time to move.
Of course, any suggestion that the "Boor" might actually be at fault for failing to either look in one's path to note the presence of others or to at least slow their approach so that others might move is as futile as trying to bail out a sinking ship with a teaspoon; the inevitable refrain one shall hear upon attempting such correction is "I did say 'Excuse me'!", usually also accompanied with rolling of the eyes, if appropriate. The temptation here to simply inflict bodily injury on the offender should be resisted; the Department does not recommend physical violence as a matter of legal course. But it occurs to this Department that our sister organization, the Department of Just Desserts, might counsel one to utter a very quick and sotto voce "Excuse me" before punching such a "Boor" in the nose, and then say, "I did say 'Excuse me'," before departing the scene. As usual, the Department of Useless Dichotomies does not specifically endorse any recommendations by the Department of Just Desserts.