Did you feel it? The Earth swung past a certain point in space; there was a little spacetime “bump” as we ran over the notch. Didn’t you feel it?
It’s kind of an important point in the cycle. Lots of people stay up to watch it happen. (Although, I grant you, the whole thing is about 10 days late. Problem is, back in the day it took them a while to recognize what had happened.)
To commemorate the occasion, some will look back and some will look forward. And some will riff on how this is an arbitrary moment in time that doesn’t mean anything at all, really.
Except that it isn’t entirely arbitrary. That’s kind of what this post is about.