Towards the end of his career, the late, great Jack Rosenthal wrote a television play called Eskimo Day, about the feelings of dislocation and emptiness that come when you see your children off to university, letting them go out into the big world without you. Quite a lot of people reading this column have, I suspect, experienced Eskimo Day in the past month.
For me, it's still a while off. But I have had a small taste of it. Because, this month, my eldest son went to secondary school for the first time. And it was a wrench to watch him go, with his huge rucksack, carrying his rugby kit and his own text-books.
Lots of thoughts went through my head about the experiences he still has to come but it did also make me reflect on the extraordinarily close community that he has now moved on from - the Moriah Jewish day School, where he attended primary school and where we still have two boys.
It hadn't been our intention, originally, to send them to a Jewish school. I hadn't been to one and, frankly, the idea hadn't occurred to me. I worried we'd be sealing them off from the world. But when we considered our options in the area, it soon became obvious that the best choice was Moriah. And - here's the thing - that the reason for that was precisely its Jewish nature.
A few weeks ago, I agreed to speak at a celebration of the achievement of establishing Jewish schools. And I do so with the zeal of a convert to the cause.
The first reason for my conversion was that Jewish schools provide parents with the one bit of choice they really have. They provide a learning environment and are infused by a spirit that is the creation of our small community.
They aren't just identikit schools printed out by officials at a Whitehall department. There is a sense of parental involvement, responsibility and control. Together, we shape our schools and define them.
I always get very cross when people look at the state system and determine that the problem is that we have too many schools like Moriah - built upon the beliefs and ethos of the parents - when it is obvious that the real problem is that we have too few schools like that. I note wryly that the people making that case often send their own children to private schools.
The second reason for my conversion is more prosaic. My children learned and are learning about the Jewish people and their religion.
The foundations are good ones and will last them for life. Yes, they do this when there are other things they could be doing. But, honestly, of all the things I learned as a child, the knowledge of my religion has turned out to be the most useful, and the least easy to pick up later in life.
And then, finally, there has been the impact on the community itself. My observation is that, across a generation, having a Jewish school has strengthened the bonds between Pinner Jews, and (this is hugely to the credit of the United Synagogue in Pinner) strengthened links between Jews of different denominations.
All this is important to say, because it is not as if the critics of the Jewish school building programme have nothing to say worth listening to.
If I can start with the simplest point, I am a little concerned (I hope there is someone keeping an eye on this) that we don't become so enthusiastic that we build more schools than the numbers can take. This would end up weakening all the existing schools. I don't want to stop any community enjoying what we enjoy, but, well, as I say, I hope someone is keeping an eye on it.
More important still, we need to understand that, while we are gaining something priceless, we must be careful to protect ourselves against what we might lose.
The Jewish community has done so brilliantly well because it is integrated. As more and more children go to Jewish schools, it means there are fewer Jews in other schools and more people, even in north London, growing up having never met a Jew.
This isn't a knockout problem (after all most people, even now, haven't met a Jew), but it is something we have to be aware of and to work at. But I am sure we will.