All the focus this weekend is on the barmitzvah boy. He’s been practising his portion, rehearsing the brachot and running through his speech. We’re all so proud of him. Because the big day is finally here. Tomorrow, my father will have his barmitzvah.

I should explain: it’s not his first. That happened in 1947. The event we’re celebrating tomorrow is my father’s second barmitzvah, to mark that moment when a Jew reaches a double milestone: the biblical three score years and ten since reaching the age of Jewish maturity. (For those now doing the maths, it means my Dad is 83.)

As it happens, this is the second barmitzvah we’ve had in the family this year. Our younger son, Sam, had his turn in April. Which means I’ve had barmitzvahs on my mind in 2017, whether hosting our own or acting as an unpaid Uber driver, ferrying Sam and his friends to or from someone else’s. And the fact is, I’ve been won over.

It’s not that I was a hard-core sceptic before. I either didn’t give it much thought or I had an instinctive discomfort with the level of extravagance some families have notoriously reached in honouring their 13-year-old pride and joy. I cringed with everyone else when I read of the £4m bash Philip Green laid on for his son, in which the musical entertainment was provided not by a couple of guys with a tape of Hava Nagila but Beyoncé.

And I was one of those who positively winced at the now-legendary Sam Horowitz video. He, you might recall, was the Dallas barmitzvah boy who made his entrance in the manner of a Las Vegas spectacular, lowered on to a stage surrounded by eight dancing girls.

I still recoil at that kind of ostentatiousness. Not least because it obscures the core idea of the barmitzvah, whose value – having watched Sam, like his older brother Jacob, go through it — I’ve come to appreciate anew. If anything, I reckon this is one Jewish ritual that’s more relevant now than ever.

For a start, it’s rare for a child that age to have to focus on a project. GCSEs are still three years away; school can feel a little lacking in purpose. Suddenly, from age 11 or 12 onwards, the bat or barmitzvah has to take on a goal, prepare themselves, work hard, get nervous, deal with those nerves and press on towards the finish line. They all know that, whatever Jack Rosenthal imagined in Bar Mitzvah Boy, his much-loved 1976 BBC play, there can be no backing out. Whatever apprehension they might feel, this is a mountain they have to climb. It’s a crucial life lesson, taught at the first hint of adulthood.

Having such a goal was probably always of value. But right now it seems especially useful. The process of preparation means that, for a few hours every week, your son or daughter has to put down their phone, turn away from the screen, and do something real not virtual. For the parent who gets involved in teaching or practice, there is scope for major irritation and the odd row, yes, but also for a very particular kind of bonding between you and your child.

On the day itself, especially in synagogue, there is something rather wonderful in seeing scores of adults obliged to listen to those who, let’s face it, are rarely heard. As individuals, we might make a fuss of our own kids, even spoil them, but we can’t pretend that, as a community, we often sit quietly and give the 12- and 13-year-olds among us the floor.

Yet, on that day, they are at the centre of the action, granted a status they will not have had until that moment. At a stage of life when children are often uncertain and lacking in confidence — especially in the age of social media, which can have such a sapping effect on the mental well-being of young people in particular — it is a serious and collective gesture of validation.

I have seen the same expression on so many kids as they complete their final bracha, beaming as the congregation cry out a big yashar koach, sing Mazeltov and start hurling sweets. Their faces look like flowers turned up towards the sun, soaking in the warmth and being nourished by it.

Above all, when so much else about adolescence is confusing, when children are trying to work out their place in the universe, along comes a ritual which says: “Here, this is what you’re part of.” You’re not just a few pictures on Instagram. You’re a member of a community, a people, that stretches deep into the past and across the world.

The Beyoncé-style barmitzvah remains an embarrassment. But the core idea is one of the great Jewish innovations, a necessary and valuable rite of passage. Which is why I raise my glass to my father and his fellow b’nei mitzvot this weekend and say: Mazeltov!

Jonathan Freedland is a columnist for the Guardian