I have reasons as well. I'm not a Christian. Except for Sweetie, my family are all far away. I miss my cousin's big family gathering (I have a lot of cousins). I don't even have a work Christmas party to go to (although I did enjoy a lovely Chanukah party earlier in the month).
Still, those things are not why I sometimes get depressed at Christmas. For me, it's because I don't "do" Christmas well. I'm not very skilled at it. Some people are extremely skilled at Christmas! And many do quite well enough at it. Sweetie is one. She's very good at decorating and excellent at finding the right gifts. Those are skills that I don't have. Christmas highlights my own holiday seasonal inadequacy. Sweetie didn't want to do any Christmas baking this year (she's good at that too), but I probably should have, because it's one thing that I actually am skilled at.
Even though Christmas has no religious significance for me, and I think much of the secular celebration is crap, I'm not really a "bah humbug" type. I love traditional Christmas carols, including the religious ones, because they're beautiful. We get a real Yule (or Christmas) tree every year, and I love that, all strung with lights and ornaments. I love Christmas food and Christmas gatherings. I love sending and receiving cards. I even love the Christmas story, although I think it's only a story. I cry whenever I watch A Charlie Brown Christmas when Linus quotes from the Gospel of Luke. The story is so beautiful that it's no wonder people think it's true, or want it to be true. So I can't just say "fuck Christmas" and not care about it. I do care.
The people who are skilled at Christmas seem to be innately good at it, but maybe it's not innate. I imagine some have more talent for Christmas than others, but maybe Christmas skill can be learned. In which case, I could learn it. I'm not sure how, but there ought to be a way. Maybe one thing is to start early. Stay alert all year long for clues from people as to what they might like and what they wish for. Shop early, ship early. Find some cool recipes and get back to Christmas baking, and give all of it away (as we have done in the past). Light more candles. I am the least craft-y person I know, but maybe I could learn to make a Yule/Christmas decoration. And maybe we could even add to the glut of Christmas parties by hosting a party of our own. Someone always needs one more winter celebration.
Christmas Eve can be hard when you know you haven't done these things, and it's far, far too late to start. So I will just have to make next year different. I've done that in other areas of my life. Why not Christmas too?
Meanwhile, chapeau! to you who love Christmas and are very good at it. I have great admiration for you. And I envy the happiness you get from the season and appreciate when I am the beneficiary of your Christmas largesse. I'll have what you're having.