A key aspect of how Eastern Orthodox Christians celebrate any liturgical feast is in our preparation for the feast. In preparation for the Nativity of Christ, Orthodox Christians fast, according to their capabilities, for the forty days leading up to the feast. We do this to prepare the lowly caves (mangers) of our hearts – which are home to the irrational beasts of passion – to receive Christ during the Divine Liturgy on Christmas Day.
Fasting in the Orthodox Church is not just an exercise in food selection or portion control but includes almsgiving, mindful abstention from potentially harmful words, deeds, and actions, as we prepare to celebrate Christ’s Incarnation. But the Church never forces the individual. While Church stresses participation in this cycle of preparation and fulfillment (because it can be life-giving!), Orthodox Christians are free to do as they like to prepare (or not prepare) in this manner.
Small “t” traditions vary in local Orthodox communities – such as the time of Liturgy, what the community does afterward, how people celebrate with family, and so on – but the means of preparation is the same. But one thing is for certain: the primary reason we celebrate Christmas is because Christ is come, in the flesh, to heal the human person.
And so the Church beckons us to taste and see that the Lord is good.
Perhaps at some point you might consider having a real-life discussion on making the paradigm shift from the US/Protestant cultural approach to the advent season, which is a time of happiness, generosity/charity, parties, carols, and decorations, to the more penitential and somber Orthodox approach...around which evolved the Medieval and Eastern European Christian cultures. As an inquirer, I'm honestly finding this difference, and I'm certainly not an exuberant, extroverted, or gregarious person, to be very disconcerting. I know Orthodox are suspicious of the passions getting out of control, but do you think they ever just experience joy in God's blessings?