One of my favorite books is the autobiography of the children’s-book author and theologian C. S. Lewis: Surprised by Joy.  It’s the story of his childhood, adolescence, and conversion to Christianity, and when he tells the story, he builds it around his repeated experience, in different times and places, of “joy.” He’s careful to say that he doesn’t mean “happiness” or “pleasure.” “Joy” is something different: a sudden longing for some enormous beauty outside oneself, a sudden stirring in the soul that catches a glimpse of eternity in the midst of this world and longs to hold onto it forever. He finds it in various places and ways—in his imagined world of “Animal-Land” and in ancient Norse myths, in the tiny beauty of his brother’s toy garden and in the awe-inspiring love of the Christian gospel—but again and again it appears in his life like a road-sign to something beyond his quotidian concerns, and then it disappears, leaving only the longing to feel it again. As he matures, he writes, he experiences this feeling of joy less often; not because he’s less joyful, but because he’s already traveling the road of joy. He doesn’t need the signs any more to point the way.

Joy, in this sense, is a kind of nostalgia. Not “nostalgia” in the way we usually mean it as a kind of sentimental appreciation of the past. “Nostalgia” in its oldest and truest sense: a kind of painful yearning to be at home; really, a kind of homesickness. When the great hero Odysseus has been away from his family twenty years, ten at war and ten wandering his way home, he’s falling apart inside and what he feels is nostalgia: literally “the homecoming-pain.”

We all feel nostalgic now, and not just in the sentimental sense. We all yearn deep in our hearts to come back home, to return to the way of life we’ve known and loved. This nostalgia is worse than ever in these strange weeks before Christmas at the end of this strange year.

But it might be worth remembering that our longing is itself a kind of joy. Just as C. S. Lewis’s flashes of joy pointed him toward a greater and eternal joy, reminding him that something existed out there beyond his own life, so our homesick longing is the reminder of joys once shared together, joys that one day we will feel again. So when you feel that longing for what’s gone, rejoice in your memories of the past; and rejoice in your hope for the great joys still to come.