The best way to have a Merry Christmas is to not focus on the fact that paternity tests didn't exist 2000 years ago. (Picture of Joseph with a cloud over his head next to Mary holding a baby.)
Oh my god, the department stores have put up Christmas decorations already. Every year it's earlier and earlier. Civilized people like you and me understand that Christmas shopping starts on Christmas Eve, and in a heightened state of panic mingled with resentment and lots of mental swearing. You know what's ironic? I bet Jesus' parents didn't even celebrate Christmas.