An acquaintance asked, ‘Have you got her a toy cat yet?’

Reading my expression as one of incomprehension, she elaborated: “You know, a teddy-bear cat, something she can pet?”

A year ago my understanding of the raw end of dementia was less well developed than it is now. I was still straddling an innocent’s position of denial and disbelief. So the look on my face that day wasn’t just because I didn’t grasp the question.

It was because I was appalled by it.

It happens at roughly the same time of day: sundowning. But this is more than the slip of day to dusk. In the case of dementia, “sundowning” is the significant personality change that can beset sufferers towards the end of the day.

Before my mother presented with Alzheimer’s, I didn’t give the disease much thought. If I forgot something, I’d roll my eyes, laugh, and ask, “What am I like?” Or excuse myself as having had a senior moment. And then I’d forget about that, too.

Now when I forget something – anything – I’m seized by fear. You don’t think about dementia until you have to. And then it’s almost all you think about. I’m terrified I might one day suffer with what my mother suffers today.

Sure enough, cuff tight about my arm, my heart pounding, the machine beeping, it gives a reading higher than it should be: 140/90, diagnosed as hypertensive Stage 2.

“I promise you, it’s not normally that high!” I bleat.

How does a memory take root safely so that it sustains, deep and permanent within the structures of the brain? An archive of our past neatly filed away for reference later. A map: the who and why and where of every part of us.

A word that speaks to a robber of language so that my mother must say, “I went to get that thing with words in it”. She means a book; a book she mostly cannot read and certainly cannot understand. A word that would describe the manipulator of moods and minds so that my gracious mother turns on me in uncharacteristic fury or treats me with the disinterest of a stranger.

Is this because we live longer – and in our dotage is a window of sinister opportunity flung open to create a crack for this disease to slink through? Is it hormone related? Is it because our neuro-protective oestrogen dries up at menopause so our brains begin to dry up too? Or is it because our testosterone levels are far lower than men’s?

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It is early last summer. Ireland is anticipating liberation from lockdown. I am researching Airbnbs. I have bossily corralled my siblings into a holiday. Us and Mum, I say.

It is important, I urge, “before she forgets us forever”.

The day my mother forgot who I was, I was so shocked I laughed; I thought she was joking.

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