I grew up surrounded by screaming schoolgirls. Few of them – none, in fact – were screaming in my direction, dazzled by my good looks, but many were screaming at the heart throbs of the day. There were plenty of them, including the Bay City Rollers, the Osmond Brothers and David Cassidy.

Some have aged better than others. Donny Osmond looks terrific for a man in his 60th year and has a full head of brown hair, even though most of it used to belong to someone else. The Rollers roll on, looking their ages and some. And there’s David Cassidy, another member of the dubious hair department.

I own a David Cassidy song, I Think I Love You recorded by the Partridge Family in 1970. I thought, still think, this was a fantastic pop song and his solo stuff was okay too. From a so-so cover of the Association’s Cherish, Could It Be Forever, the double-A side (ask your parents’, kids) I am a Clown and Some Kind of a Summer and who could forget How Can I Be Sure? Many girls had pictures of Cassidy on their bedroom walls (they told me this: I never got near finding out) and he was everything a young girl wanted. He was a big star. Then I check my book of hit singles to find a simple fact: his best years of music ended in 1973. It was all downhill from then on.

Since his star began to fade, so did his life. Drug problems,divorce, alcoholism and bankruptcy. All pale into insignificance compared to his latest trauma. David Cassidy has dementia.

David Cassidy is 66 and by today’s standards not especially old. He can still knock out a decent tune, there’s a few bob to be made on the nostalgia circuit and he has some of his best years ahead of him, except that now he hasn’t. Much was made of a recent performance when Cassidy shambled through his songs, forgetting the words of his biggest hits and now we know it was nothing to laugh about.

Bravely, Cassidy has gone public with the news of his dementia, for all we know to put an end to the spiteful speculation and piss taking TV interviews by the likes of Eamonn Holmes. Dementia, says Cassidy, runs in his family and he was not surprised by it and he will know better than anyone the dark road on which he will now travel to nowhere and nothingness, slowly but surely filling him with emptiness.

There were times when I would have loved to have been David Cassidy, with all that fame, all that money, all those girls. And now this, the illness we dread like we dread cancer, maybe even more so, because dementia means a living death.

Good luck with the fight, David. From now on you should be accorded the privacy and peace you need and deserve. Not that you are alone because we all wish you well.

When we are young, we can never imagine this, or something like it, might happen to us, to someone we are related to or just know or to a pop star we idolised. But it can, it does and it probably will.

As he once sang: “How can I be sure, in a world that’s constantly changing?”