POOR old Paul Burrell.

Eating kangaroo undercarriage and sticking a shaking hand into a vat full of squirming rats must seem like child's play to Diana's Rock now that he's come face to face with the real king of the jungle in the shape of Michael Mansfield QC.

As Paul stands there in the witness box, is he inwardly screaming: "I'm a celebrity, get me back into there!"? My money says yes. At least, I reckon he would be if he could only remember ever having been on the show.

Don't misunderstand me. I have nothing but fellow feeling for the unfortunate Burrell and his struggles at Diana's inquest.

Under close questioning from the formidable Mr Mansfield, he couldn't remember whether he had a journal or a bundle of notes, whether in fact he had actually destroyed all his records, and which of Diana's secrets was the big one: the one that he was never going to give away.

After this uncomfortable exchange, poor Paul then made a miserable traipse up to the Burrell homestead in Chester in order to retrieve such documents as might or might nor still be in existence, so that the coroner could decide if they were relevant to the inquest.

You could say he'd brought it all on himself, but the truth is, I couldn't remember my own name if I were in Paul Burrell's shoes - and God help him if he's anything like me when it comes to finding stuff around the house.

As I write this, I am squinting at the screen with a bit of a headache coming on.

Yet again, I have managed to leave my glasses at home because my grey matter is shrinking faster than the polar ice caps.

It's happened to me this time because I was concentrating so hard on remembering the important letter that I have to send off: yes, the one I forgot to post yesterday. I've got the letter with me now: I just can't check it through properly because the print is a bit of a blur.

I think I checked it at home, but I can't be sure, because my failing memory is starting to dog my shadow in another way now.

Once upon a time I could remember exactly what I had said and done. The photographic memory of it was stored safely in my brain, ready if necessary to be screened again, in glorious Technicolor and in minute, eagle-eyed detail.

Nowadays, I struggle to remember something said to me half an hour ago, and even if I feel pretty sure about the who, the what, the why, the where and the when, all someone has to do is disagree with my version and my history is rewritten.

There's always the nagging doubt that the other person knows better than I do what I did this morning. I'd make a lousy witness, so I can find it perfectly understandable when someone like Burrell isn't sure what day it is.

If I were him, though, the thing that would be worrying me most of all is that secret of Diana's. Whenever someone tells me something in confidence, I am instantly filled with dread that one day I will have grown so gaga that I let it slip because I have genuinely forgotten that it was supposed to be a secret.

Might we already know, without realising it, that secret of Diana's?

What a shame if we did. After all, there's no secret more exciting than the one you've not been told.