It is rather like that with New Labour. The rationale behind some of its policies may be obscure but you assume that there is some larger purpose, and that the role within it of each ministerial initiative will eventually become clear. But I am beginning to suspect that New Labour is just a series of random responses to random events.
Certainly, ministers keep falling out of windows. They raise the basic state pension in line with inflation, as governments have done for many years, the idea being that pensioners are no longer by definition impoverished and help should be concentrated on those who need it. Then there is a national outcry and pensioners get an above-inflation rise.
Ministers use the fuel-tax escalator - increasing petrol duty annually above the rate of inflation - to discourage car use and reduce road congestion and global warming. Then lorries blockade fuel depots and the escalator is gone.
So it is with education. For just about my entire adult life, almost everybody has agreed that the English sixth-form curriculum is too narrow and specialised. Successive attempts to reform it failed. The "gold standard" of A-level had to be preserved. (Has nobody explained to today's politicians that the Treasury abandoned the real gold standard in 1931, because it proved disastrous for British industry?) Parents and employers, it was said, trusted A-levels, though what this really meant was that newspaper editors and backbench MPs trusted them.
Then came New Labour's system of linked AS-levels and A2s. It always struck me as an uneasy and messy compromise. Because the public was promised that the "gold standard" would remain in place, there was bound to be an argument about standards, just as there was when O-levels were absorbed into GCSEs.
To be honest, I never quite understood the new system, though I did not dare confess this to Baroness Blackstone (then an education minister) after she had patiently explained it to me. I did not see how it could compel universities to look beyond the usual three specialist subjects when selecting students - and in last week's TES, a recent sixth-former confirmed that "most of the universities I spoke to actually wanted students to have three full A2s".
Nevertheless, I assumed that ministers had some idea of what they were doing. True, they had created something so complicated that nobody understood it; but that is not in itself a reason for abolishing something. But during the summer they fell out of the window when the row over A-level grading occurred, and were panicked into setting up an inquiry under Mike Tomlinson.
I doubt that Mr Tomlinson, clever though he is, understands the new system. Otherwise, he would not have suggested that A2s and AS-levels should be uncoupled and then go on to hint that entry to A2 might not depend on the completion of an AS course. This would surely just leave us with the old system, where university students do three specialist A-levels; and we would lose even the small hope of greater breadth offered by the new system.
I wait for the loose ends to be tied up in the next episode. But like Mr Cocker, I have grown up and I know that they won't be.
Peter Wilby is editor of the "New Statesman"