PETTY and sly. That is how I would describe the shadow that hangs over more and more of our parents and grandparents.

Dementia, Alzheimer’s or just old age seem to have crept up on us, silently and stealthily; assassins of our dignity and pride, striking like a slow-acting poison during that period so obscenely labelled the ‘golden years’.

If only it were that.

Instead, this last week I have seen all vestige of whom my mum and dad are, and were, and could be, utterly erased in the blink of an eye.

My mother, an old-fashioned mum, who was always there when I got back from school and every Christmas made me write ‘thank you’ notes, has now all but slipped away.

Not physically, but mentally and spiritually.

And my dad, once a proud naval officer (“Son, did I ever tell you about the time I was stranded in Trinka Mali with Rasher Bacon and Chalky White....?”) last week described my weekend visit – to my brother – as “a bit of an inconvenience, but he seemed a nice enough chap who didn’t push his luck so I asked him to leave on Monday”.

The combination of my mum’s age, her Parkinson’s and the heavy drugs used to control it have finally taken their toll; so much so in fact I think even Doctor Who would be hard pressed to pinpoint the precise timeline she currently exists in.

My dad, older still (86), whose sole purpose in life over the past five years has been to care for his wife, now feels completely disorientated by her relocation to hospital and probable long-term commitment.

After 64 years, it must be as if the very spine of his existence has been torn out and discarded and, as such, his short-term memory has followed the same route.

The NHS have, so far, been super – they haven’t intervened too early nor left it too late, and now they have grasped the nettle, there is a sense that a practical, workable solution can be found in the next few weeks.

What has shocked me, however, is the way this modern plague – because that is surely what it is – strips those it affects of their pride and dignity with a gleeful wantonness that borders on obscene.

Indeed, it seems to delight in reducing its victims to an existence fuelled only by the petty, spiteful and suspicious minutiae of everyday life, eradicating all humanity and empathy like a cancer of the soul.

For someone who has spent his life in hiding, shielded by smart quips and a supposedly impregnable confidence, it’s been a wake-up call I wish I could have slept through.

And, like my dad, I feel disorientated. And angry. And maybe just a tad suspicious of how all this could have happened.

At least we have that in common now...