My routine is identical every year.

I watch the last child leave the church — the first Christmas Eve service rehearsal officially in the books — then I drive home, unlock the front door, set my purse and music down on the front entryway bench, walk to the living room, lower myself onto the couch, and cry.

I usually cry for the entire afternoon.

It’s not that I am unhappy. It is that I am sad-happy.

So many hugs. So many songs. So many curious queries. So many eager entreaties for personal attention. So many little heads turned toward mine for affirmation. So many children, and none of them mine and all of them mine.

My barren heart overdoses on the sweet stimulation, and it comes out as salt water on my pillow. Grief is strange that way. It’s triggered by happiness. To be loved stirs up memories of loves lost. So many children, but none of them from my home. None of them in my home.

This year, the tears started long before any of us left the church.

“Christ the child was born for you!” the children sang into my face. The words entered my ear but landed in my heart. “Christ the child was born for you!”

The final chord faded, and the children — my children — stared openly at my red cheeks, my wet eyes. One of them giggled nervously.

“It’s okay,” I reassured, wiping at the river. I tried to think of anything but the present moment. It wasn’t time to commit to the annual cry. Not just yet. I took a deep breath. “Do you realize what you just sang to me? Those words are so comforting. Jesus was born for me! He is born for you! Thank you for comforting me with your song.”

The children simply watched, mystified.

“I will try not to cry when you sing on Christmas Eve,” I winked, still wiping, “but I might. This song comforts me, and I sometimes cry when I am happy.”

One boy scrunched up his nose. “People cry when they’re happy?”

“Adults do,” I said. “At least, some of them.”

“Why?”

No one was giggling anymore. Everyone was listening.

“I think,” I started, “it’s because adults have known a bit of sadness in their life, so when they hear something comforting, it relieves them of their sadness. Crying is a way of relieving sadness. It is a way of being happy.”

It could be explained better, I think, but the children took my answer in stride. They usually do.

We sang some more songs. We practiced some more notes. Before the children left, some of them waited in line at the piano to tell me some of their wishes, to confide in me some of their hopes, to cry onto my shoulder some of their own sadnesses, and to hug my heart close to theirs.

Such sweet stimulation. Such sad-happiness.

I cried the rest of the day.