For children this is a day of anticipation, joy and magic, a day when for just a moment nice overcomes naughty.
For adults this is a day of reflection and tradition, a day when without warning melancholy memories of Christmases past overshadow the excitement of today.
For children this is a day of confusion. Is this a day we honor the baby in the manger that was given gifts of frankincense and myrrh -- whatever that is?
Or is this a day reserved for a jolly bearded fellow who hangs out with elves and travels with a bunch of reindeer?
For adults this is a day of pressure.
Did we buy the right gifts for the right people? Will our kids like what we gave them? Will the sweater fit? Is the camera charged? Do we have enough ice and will the checks clear?
This is Christmas, a holy day wrapped in shiny paper where the recipes of ancient sacraments are blended with people who wear ugly ties and with silly songs about mama kissing Santa Claus.
We don't need a Norman Rockwell calendar or a reminder on our smartphone to know this is Christmas.
Every year the arrival of this special day is triggered by events that date back to childhoods of department-store Santas, trips to grandparents and meals eaten at a wobbling card table reserved for the children.
My triggers are many:
The taste of a Claxton's Fruit Cake.
Memories how an official Stan Musial baseball glove smelled the year it was under my tree.
Marveling at Charlie Brown's naivety as he falls for Lucy's tricks again.
Fighting tears when Zuzu hears the tinkling of a bell and tells her Daddy that means an angel has earned his wings.
Billy Winn's Egg Nog.
Wondering why people are enthralled at a movie about a Daisy Red Ryder BB gun.
The full-bodied sound of a church choir proclaiming "Joy to the World."
Hearing the reading of St. Luke's familiar words.
The sound of coins dropped into a Salvation Army kettle by a child.
A plate of half-eaten cookies and an empty glass of milk that proves Santa Claus was here.
Hearing our 4-year-old girl's joyful giggle as she reaches under the tree and grabs another gift.
The blessing of readers that share my ramblings about a day that we have spent together many times before.
-- Richard Hyatt is an independent correspondent. Reach him at firstname.lastname@example.org.