A former lodger in my London flat told me to bin further correspondence arriving for him, but I'm afraid that yesterday I opened a circular from the Conservative Way Forward, to see what the ginger group was up to. It looked like a routine mailshot.

It was - restating the group's purposes and urging supporters to join, or rejoin. I was not surprised it came in the name of the organisation's president, the Baroness Thatcher of Kesteven. Nor was I surprised that the letter bore her signature, in blue - printed, I assumed.

But idly I passed a moistened finger over that characteristic script, formed in her beloved blue felt-tip: the signature I know and remember so well from the long-ago years when I dealt with her public correspondence as Leader of the Opposition; a signature that even now has lost only a little of its bold sweep, betraying just a hint of frailty.

And to my amazement the manuscript smudged. She really had signed it.

My first thought was to wonder whether a machine could do this; but I don't think the Mrs T I once knew would countenance forgery. So were her office dragooning the old girl into routine clerical work? No, her small staff are devoted, and never would; though I do recall that she never, ever, thought signing letters to the public was beneath her, and we sometimes had to hide correspondence lest she grab it and deal with it herself.

So I rest on my third thought: that, anxious as she always was to do “something useful”, Lady Thatcher had insisted on doing something to help, and, at 82, was signing a great heap of form letters herself.

By last weekend I had assembled most of my Pick of the Week for BBC Radio 4 on Sunday evening. But Charlotte Green's now famous fit of the giggles on the Today programme on Friday morning - I heard it in bed - was not too late. The Times even ran a leader on Saturday remarking that “corpsing” isn't done alone but needs the presence of others.

I so disagree. I am forever overcome with disruptive but unsuppressable fits of giggles when alone, or in a public place with nobody to react except stare. Inconvenient hilarity can arise from all kinds of things, but in my case most regularly from realising how ridiculous I am. Nobody else need be involved in this.

That's not quite true, of course. We observe ourselves and quiz, advise, reprimand and laugh at ourselves - so there must always be at least two of us. But, hey, this is getting too heavy for for a chatty midweek diary, so let's leave it there.

Suffice it to say that, alone in a tent in the dark in the Andes, having reached out for what I thought was a biscuit, and eaten a lump of frozen llama dung, my splutters and squeaks of mirth would have woken any living soul within earshot. But nobody was.

Having been a bit feverish all week I may be suffering from some kind of low-level delirium - but I can't help feeling that what I'm about to describe did happen. It's just that nobody I've asked seems to remember anything about it and friends say the idea's such obvious nonsense that I can only have dreamt it.

But this is what I think I remember. That on Monday there appeared in the national newspapers a full-page paid advertisement by the Government announcing that “a new era in policing has arrived” (I'm sure I remember that phrase). And I seem to recall that there was a big speech by the Prime Minister, saying that the day “heralded” a new era in policing; and a big speech by the Home Secretary too.

The details of what this new era amounted to do, I confess, now escape me. Nobody seems to have commented on it. Ludicrously, all I can remember is something about a “dedicated neighbourhood policing team” and (even hazier here) us all being able to help them to solve “local” problems by calling their mobile phone numbers or going to a “community” meeting... or maybe text them or something... sorry, mind's a blank.

As almost all policing is “local”; as the thing you really need to contact the police about is usually a suspected crime and none of this guff helps us to do that; as government doesn't usually communicate major policy announcements by paid advertisement; and as, if anyone actually did lob this pebble into the media pond, then only I seem to have heard so much as a tiny plop... I have to conclude my friends are right. I just imagined it.

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