And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth. (John bore witness about him, and cried out, "This was he of whom I said, 'He who comes after me ranks before me, because he was before me.'") For from his fullness we have all received, grace upon grace. For the law was given through Moses; grace and truth came through Jesus Christ.
(John 1:14-17 ESV)
The Incarnation, sadly, is something we have to militantly try to remain thankful for, just like many of other blessings we receive in our lives that we grow used to, so the good things we have become less and less good to us the more we benefit from them. Indeed, in this world of Sin and corruption thankfulness is a thing that turns heads. Echo the words of St. Paul that you are learning to be content with whatever your station is in life and you can expect at least a few double-takes. Why? Because we are far too used to a fallen world where good things never last. Those gifts we unwrapped on Christmas Day will age just as we do, and perhaps wear out, or perhaps we might change such that we can't make use of them anymore, like if we received a piece of clothing that's a certain size and our size changes later on. Please don't hate me just yet. I didn't say which way our size could change, and will be glad to leave that as open speculation. :-)
But amidst our surroundings of good things either becoming less good because of age or because of our failure to appreciate their goodness, the Incarnation of Christ, that gift that we have to work to appreciate because such an idea doesn't seem to resonate with us, remains true, despite our failures and shortcomings. This Word who became flesh and dwelt among us took on our humanity, came into this world in a humble manger, wound up in the Biblical "land of bondage" in the flight to Egypt, and continued His path to the Cross on our behalf. He is the Good Shepherd who willingly lays down His life for us His wayward sheep.
Our culture likes to separate Baby Jesus from the Agnus Dei, the Lamb Of God who takes away the Sin of the World, much as they like to separate the manger from the Cross, but just like our assorted shortcomings in appreciating the glorious gift of the Incarnation that doesn't fall apart with age and isn't dependent on us remaining a certain way forever in order to be a proper gift for us, this greatest gift of all to us and for us is still what it is despite anything we do, and this Word made flesh is still who He is and is still for us, despite anything we do.
So go ahead on these remaining days of Christmastide and continue celebrating. Sing another hymn. Enjoy another evening by the fire. Watch another Christmas movie. Let our culture say what it wants about our celebration of Christmastide. This Word made flesh for us who is our Good Shepherd is more than worth celebrating.
May the peace of God which passes all understanding guard your hearts and minds in Christ Jesus. Merry Christmas. Amen.