Now, it's going to be hard. Most of us, down in, want to keep the people around us happy. Since we do, we end up going crazy every year looking for perfect gifts, shopping, traveling every weekend, baking, cooking, generally going nuts lest we upset someone and ruin their Christmas. We don't think about what we're doing to ourselves, and chalk it up to 'not being selfish at Christmas.'
You are not being selfish to realize that Christmas is not about you, your family, Santa, or presents. It's about celebrating the Lord Jesus Christ. We've attached so much other things to that celebration, it's like we're having a birthday party, but insisting that everyone present get gifts, be made happy, satisfied, everyone but the One who the party is for. Would you want someone to make your birthday all about themselves? No, but we do it every year at Christmas.
And to those of you who think Christmas can be ruined: If you allow someone the power to ruin your celebration of Christ, your worship of the One who died for you, your relationship with Him needs some fixing. If someone tells you that you are ruining their Christmas: point them to the manger, the cross, and the empty tomb, and lovingly remind them that Christmas will only be ruined by ignoring who Christ is.
I will celebrate, I will go to the parade, some parties, I will give and receive gifts, because these activities are not bad in themselves, but they are no substitute for reflecting on Christ this year. Make a habit of taking 5 extra minutes to focus on Christ for the next 25 days. Then keep that habit.