He or she who has not Christmas in their hearts will never find it under a tree, or in a movie, or at a dinner with all the trimmings in a fancy restaurant. We went looking for it in a church in Limerick city on Friday.
Since she was a baby my daughter has had Angela and the Baby Jesus read to her every Christmas Eve. It's a tradition in our house.
She loves the story of six-year-old Angela making her way along the gas-lit streets in the cold to St Joseph's Church in Limerick in 1914 and seeing the Baby Jesus lying alone and cold in his Christmas crib, and feeling so sorry for him that she takes him home to keep him warm.
Turning six herself in February, my daughter was delighted when I told her that we were going to visit where Angela lived. "Will we get to hold the Baby Jesus?" she asked excitedly - I was hoping for a pint in South's, the pub on Quinlan Street where Angela goes on Christmas Eve, and which Frank McCourt's "shiftless loquacious alcoholic father" was too fond of in his time.
She has watched 2018's Angela's Christmas on Netflix dozens of times and, of course, she and her two-year-old brother watched the sequel, Angela's Christmas Wish, twice - you try and get the TV remote off a young child at this time of year - on the night before we set off on a pilgrimage to see Angela.
It is box-office Christmas cheer that the Baby Jesus, who Angela pinched from the church in Angela's Christmas, is wearing a jumper to keep him toasty.
Arriving just before 11am, there was a fantastic Christmas buzz to the wonderful city Brendan Behan described as a place of "piety and shiety".
Going into the famous old church on Quinlan Street and O'Connell Avenue in Limerick was like entering a magical other world for her and her younger brother.
I realised it was inside this church in January, 2018, that the body of poor Dolores O'Riordan lay in an open coffin as thousands lined the streets of her home town in the rain to pay their last respects - Dolores sent my daughter a present when she was born in February, 2015.
It was outside St Joseph's that Frank McCourt saw his poor mother begging - "the worst kind of shame". Young Frank once begged a pig's head for Christmas dinner.
It was inside St Joseph's that young Frank went with his father to see the sacristan about becoming an altar boy.
Frank recounted his version of what happened in Angela's Ashes: "He says, we don't have room for him, and closes the door. Dad is still holding my hand and squeezes till it hurts and I want to cry out."
On Friday in St Joseph's there was no sign, sadly, of Angela, nor Baby Jesus. The latter won't arrive until Christmas Day.
If the Baby Jesus had been in the crib I would have had some job stopping my daughter from stealing him and taking him back to Dublin wrapped up in a Christmas jumper.
Sitting in the church, I wasn't thinking of the Baby Jesus. I was thinking of a certain baby-faced author. I remembered the times I spent with Frank - in Rome, Dublin and New York, but never Limerick.
He told me once how he couldn't understand how his father could walk away from his children and leave them to starve. I reminded him of what his brother Malachy had said, about their father having a disease called alcoholism. And he replied: "You can't walk away from cancer, but you can walk away from a bottle. So I don't absolve my father completely of his responsibility for what he did to us."
We spent Friday night in town. For the kids it was a fairytale of Limerick. The 38-metre high panoramic wheel on Arthur's Quay Park and the lights all along the boardway lit up the Shannon running through the heart of city. For the adults, it was an opportunity to enjoy a great night in a modern city.
Yesterday morning, I felt the pull of Frank and went back to St Joseph's on my own. At its best Christianity gives us something to guide us in the dark, something pertaining to truth. However controversial it turned out to be, Angela's Ashes was Frank's truth.
"They can argue as much as they like," he said of his critics, "but I wouldn't dare intrude on their story." He also said he would have died "howling" if he hadn't written the book and asked God "for one more year".
He might have had a turbulent relationship with his birthplace, but he loved Limerick until his dying breath. A year before he died, he told the Limerick Leader that he envied the people in his home city who are young and growing up in a place that was "buoyant, optimistic, bursting with energy".
But Frank McCourt, too, is part of the story of the modern, confident Limerick city.