I mentioned way back when that elves had superstitions regarding numbers. Odds, especially three and nine, were considered to be positively charged numbers, and evens were considered to be negatively charged numbers.
This will interest historians, because it was a major sticking point between the elves and the ancient wizards, because the ancient wizards were quite enamoured with powers of two. The ancient calendar has exactly 512 days in a year (2 to the power of 8), each day is divided into thirty two hours (2 to the power of 5), each hour is 64 minutes (2 to the power of 6) and so on. The elven calendar goes to great length to avoid this, which is difficult, because a solar year is, in fact, exactly 512 days long. This issue between the elves and the ancient wizards was often ignored but never resolved.
For many elves of the default time period, numerology is somewhere between superstition and tradition. Some elves really believe that even numbers will cause the will of nature to be jumbled, despite the fact that mating usually occurs in pairs (if I could explain it, I would, but they don't tell me these things).
A larger proportion of elves would say, if questioned deeply about the subject, that they don't really believe that having two of something will cause any negative effects, but still make sure that their bouquet of flowers has nine and not eight or ten, and they won't even think about it. This reaction to numbers is so ingrained in their psyche that most elves would be confused and surprised when you pointed it out to them, because it's the way they've always done it.
I'm not going to go into great detail about the various specific superstitions regarding some numbers, but I will eventually get down to it on the wiki. These little facts are less important than getting the psychology down.