Many children are natural performers and born show-offs, especially when there's a television camera crew around.
Kids + TV + Nativity play = Fun, right?
Well, it should.
Here, though, the equation added up to a needlessly ponderous, confused, unfocused film that leapt about all over the place, flitting from Scoil Mhuire in Ballyboden, Dublin, to St Joseph's, Templemore, Sligo, to St Columba's, Douglas, Cork, to The Model School, a Church of Ireland institution in Baileboro, Cavan so frantically that it eventually became wearisome.
In Scoil Mhuire, sisters Biddy and Caprice Conroy were chosen to play Angels No. 1 and 2.
"Anybody who knocks on our door, there's always room at the inn," said the school principal, resorting to a groan-inducing pun.
In St Joseph's, a girl called Aine, who studies speech and drama, and her sister Maebh were both cast in the Nativity play, while their father happens to be the school bus driver.
It's a 50-year-old school with just 32 pupils, which in itself is remarkable in this age of overcrowded classrooms and inadequate teacher numbers.
Beyond stating this fact, however, the film made nothing more of it.
In all-girls school St Columba's, Lizzie, who was born in Nigeria and came to Ireland four years after her mother had settled here, won the coveted role of Mary, while the part of Joseph went to Kerrie-Jo, who was born profoundly deaf (the school has a specialist unit for deaf children).
Her father died recently, which must have made Christmas a difficult time.
All of them seemed like lovely kids, and the teachers and principals dedicated to their profession, but beyond showing us that, I'm not sure what we were supposed to make of the documentary.
There were some vague musings in the voiceover about how the school Nativity play is "a significant family ritual in Ireland".
Is it really? Who decided that? The film's producer?
Maybe it's just my godless, lapsed-Catholic secularism, but from my experience the Nativity play is usually an opportunity for the children to play dress-up and the parents to take some pictures and make some memories.
First and foremost it's supposed to be fun, something this documentary, which needed a light touch but got a treatment as heavy as a soggy Christmas pudding, wasn't.
It might have been better to chop it up into four 15-minute segments, transmitted over consecutive nights.