The song "Twelve Days of Christmas" always bothered me because it felt unstructured. I don't care that it's nonsensical (which it is), but I was annoyed that the nonsense didn't seem to fit together. Fortunately, Snopes has cleared up one of my major complaints.
Some misinterpretations have crept into the English version over the years, though. For example, the fourth day's gift is four "colly birds," not four "calling birds." (The word "colly" literally means "black as coal," and thus "colly birds" would be blackbirds.) The "five golden rings" refers not to five pieces of jewelry, but to five ring-necked birds (such as pheasants). When these errors are corrected, the pattern of the first seven gifts' all being types of birds is re-established.
Although Snopes doesn't note it, the first seven days of Christmas are in the old year (December 25th - 31st), and the last five days are in the new year (and represented by people). Now that's pretty interesting, and I'm sure it has some sort of significance and isn't merely a coincidence.