Christmas for me is all about nostalgia and quietness.
As a kid I used to feel like the whole world was on "pause", not just on Christmas but during the whole two weeks of winter break. Last time I remember feeling that way was at age 16. I still feel some of that fuzziness during the season, but it hasn't been the same.
Also despite not being religious, most of my favorite Christmas carols seem to be the more religious ones.