Does it often happen, that you have an idea how a phrase should be used? Your idea might fly in the face of your friends and contemporaries. Example; "a couple". Now I have known that phrase to mean two, or three. I find this usage common in conversation. I logically know that it means only two. To talk about three or more, "a few" must be used.

From the other direction though, why can't I use "the other day" to describe future events? There is no past or future connotation with this phrase. It sounds odd in conversation, that's true. But only until you get used to it. I think it makes sense to be able to use "the other day" to describe events that have happened or will happen on any day other than the current one. The other day it will become acceptable.