2. 12 is the largest number with a single-syllable name, so think of all the time we'll be saving saying "2012" instead of "2011." (That said, there were more rhymes for 11, including a few that are much more useful in poetry than "shelve." I'm thinking of "heaven," "seven," and "leaven.")
3. 12 feels nicely stable and satisfying, because of the familiar concept of a dozen and the number of inches in a foot. I guess that's why the 12 Steps program has 12 steps. And why there are 12 persons on a jury. You have 12 pairs of ribs too, you know. 12 months in a year. 12 hours on the clock.
4. Here's the etymology of "twelve" (which highlights the oddness of its being "twelve" and not "twelf"):
O.E. twelf, lit. "two left" (over ten), from P.Gmc. *twa-lif-, a compound of the root of two + *lif-, root of the verb leave (see eleven). Cf. O.S. twelif, O.N. tolf, O.Fris. twelef, M.Du. twalef, Du. twaalf, O.H.G. zwelif, Ger. zwölf, Goth. twalif. Outside Germanic, an analogous formation is Lith. dvylika, with second element -lika "left over."So it's basically "2 left" (and 11 was "1 left"). It's the same concept as the "-teen" numbers, relating the number to 10, but 12 and 11 use subtraction — what is left after 10 is removed — and the "-teen" numbers use addition, with "-teen" meaning "ten more than." I wonder why. Does it have something to do with the development of a child? If the child is 11 or 12, you think of taking him back to a younger age, but at 13, you picture him standing on a foundation of childhood and building from there? If that is so, then maybe 2012 is the last year when we feel we've just entered the new century/millennium, and next year, we'll feel we are truly in it.
5. 2012 is the last year when we won't have a name — a name that we actually use — for the decade. Next year, we'll be in the "teens." Don't tell me there really was a name for the first decade of the century. You can concoct something — I'd say "the 0s," pronounced "ohs" — but we didn't call it that casually and naturally, the way we said "the 80s" and "the 90s." The first 12 years of the century have been a weird respite from focusing on the decade-ness of the decade. And that has had some subtle effect on us. 2012 is that last year to experience that effect. And then next year, 2011 and 2012 will be swept into the decade that will thenceforward be called "the teens."
7. We'll ring in the new year at 12. At 12 it will be 12. Unless you're very young — and also very optimistic — you can't think that there will be any other day in your life when at 12 it will be 12. Unless you're extremely old, you've never before had the chance to realize: At 12 it will be 12. How stunningly unique today is!