Gordon Brown left Downing Street in 2010. Sixteen years later he is still at the table. Keir Starmer brought him in to advise on the G20 that Britain hosts next year, and Andy Burnham has kept him there.

Two Prime Ministers, different politics, different problems, and both of them arrived at the same answer. There was a job that needed doing, somebody had done something like it before, and they picked up the phone.

Construction does the opposite almost by default.

I spent an hour this morning with someone who builds intergenerational learning programmes, and we kept arriving at the same place from different directions. This industry spends a fortune worrying about the people coming in and almost nothing on the people going out.

What actually walks out of the door

A commercial director retires at 60 and leaves with a body of knowledge nobody has ever written down, largely because none of it was ever the sort of thing that could be written down.

The claim he settled without going anywhere near adjudication. The subcontractor who always went quiet in month four, and what that quiet actually meant. The reason that form of contract falls apart on a live hospital site with a working A and E next door. The conversation he had with a client director at the exact point where the relationship could have gone either way.

Then a graduate hits the same wall three years later and learns it the expensive way, on a live job, with a number attached.

We treat that as the natural order of things. It is not. It is a choice made by nobody ever quite making it.

The alumni question

So here are three questions worth sitting with.

Who has left your business in the last two years that you could still ring tomorrow?

What would it actually cost to keep twenty of them on a list as alumni advisors, on a day rate, for the two or three calls a year where their judgement saves you six figures?

And what is it costing you not to?

They have not disappeared. They are still here. They are simply no longer on a payroll, and this industry treats that as though it were the same thing as being unavailable.

It is like grandparents. Most of them are perfectly happy to be asked. The insult is never being asked.

If Downing Street can keep a former Prime Minister at the table for the G20, a tier one contractor can bring a former commercial director back in for a bid.