I don't know if I get you right. I just try now.
When you're down and see all those happiness around it can be really hard to not let yourself go. You ask yourself things like what sense does this have - how can they be so happy, and some of them even aren't really happy and just pretend to be.
To many people christmas is a time that reminds them being lonely - just because it is a time to spend with family and friends. I myself often wondered whether I really should smile when I don't feel at all like smiling. It seemed wrong. That is the other way round - letting a "happy and joyous time" influence people to hide their grief seems just as ridiculous.
But it really isn't in my opinion. I learned smiling by forcing myself to smile. There is a time for everything: to suffer, to be sad, and to let go of both. Just around christmas time it seems to be really hard to finde the right grip on it.