[LeGrande]

Yes, I remember that one. But like the article said there was an earlier better one. I remember it had a reference to being to stupid to know how to pour water out of a boot if the instructions were written in it or something like that.

[Alamo-Girl]

Well, it's not water and it's in the second paragraph of the one I linked. Another version attributes it to the way we say things in Texas instead of the Army.