Some years ago now, I sat down to write a book about public services, partly because I was so angry with the way the Labour government had subverted them - making them more expensive and less effective - and partly because I hoped to provide an agenda for Nick Clegg, in case he ever became leader of the party.
The trouble was, I was too angry. I had to re-write the book twice before it was finally coherent enough to be read, which it is being now, I'm glad to say (The Human Element). By then, Nick Clegg had become deputy prime minister.
Ah yes, the travails of an author's life.
I mention it now, having read the interview yesterday with Jeremy Browne in the Times, because I wonder if my rage at the last government for their public service record was a sign that my wonky trolley (as he put it) veered to the left or that it veered to the right?
The wonky trolley metaphor is Jeremy's not mine. All parties have a few wonky wheels, but then so do we all as individuals. Some of us veer of left or right at the slightest provocation. The unexamined trolley wheel is not worth pushing, but - having examined my own wheels pretty closely - I still can't see which way they veer.
Maybe it is obvious to everyone around me, and they daren't tell me, but it isn't obvious to me.
We have to be kind to Jeremy Browne, who hasn't finished his deprogramming after his escape from the clutches of the Home Office.
He is right that the Lib Dems will be making a mistake if they paint themselves too much as outsiders in the coalition - they haven't often got their own way, but there are achievements of recent years they will want to share the credit for.
I know, it won't be the bedroom tax, or subsidising Chinese nuclear companies. But if there is nothing Lib Dems are proud of, then their tactics would be quite different - and some of what they are proud of is not going to be their achievement alone.
He is also quite right that the Lib Dems have the occasional wonky wheel. Some undoubtedly veer to the left, whenever the party starts worrying about private ownership instead of scale and flexibility and humanity.
But it worries me far more when it veers in a corporate direction - suspicious of what people and communities can achieve on their own account. When it puts safeguards ahead of community enthusiasm (free schools). When it prefers centralised solutions to local ones (nuclear energy).
But they also have another wheel that, rather than veering, just stays completely stuck - so stuck that you might imagine it veers the trolley to the right. It is the wheel marked economics, and for some reason - even when they put on their glasses - many Lib Dems are unable to see it.
I've wondered often why this is. I think it is because, when socialists are naive about power and can't see it as a problem, liberals tend to be naive about money in the same way. They somehow see it as outside their responsibility - isn't Captain Mainwaring dealing with that? (No, he's been replaced by risk software at regional office).
This is not a criticism of Danny Alexander, who has been very effective, but his responsibility is saving money, not shifting the way the economy works.
But the real problem with the trolley metaphor is that assumes the right path for a Lib Dem trolley is rigorously central, turning neither this way nor that, as if Liberalism was about compromise. Whereas the truth is that the absence of the Liberal tradition in UK government for a century has been a tragedy for this country and the world.
No, the problem with the Lib Dem trolley, as far as I'm concerned, is not that it veers one way or the other (though it does), but whether all its wheels are working - and, above all, whether it is designed to move in a Liberal direction in the first place.