A kind reader wrote to express gratitude for the Post’s series of articles on dementia. He was 85 years young and still active, although only going to the gym “four times a week now”, which made me smile. In his spare time, he listens to music CDs.

What is good for your heart is good for your brain.

This is the message many doctors share. They include Dr Albert Hofman, chair of the department of epidemiology at the Harvard T.H. Chan School of Public Health at Harvard University, in the US state of Massachusetts.

We have known for almost three decades that some peoples’ brains can function normally even when riddled with the plaques and other damage associated with dementia, due to an enigmatic capacity called cognitive reserve. Yet despite growing evidence of its importance, it has been challenging to pin down how this quality operates in the brain.

The diagnosis felt like a gut-punch. Had I done something as a mother to cause this? Had I failed to do something to stop it happening? I felt both guilt and fear – guilt because, as parents, we shape our children. If my daughter struggled with mental illness, had I damaged her in her early years?

People often say, “It’s not your mother, it’s her dementia.” An unhelpful observation.

I know: I know that when my mother is unkind or impossibly difficult it’s because her empathy and characteristic sweetness are being eaten away by Alzheimer’s. Understanding that the fundamental changes in her are because of disease do not make them easier to live with.

I never thought about dementia until I had to, until my mother clearly and obviously presented with symptoms a few years ago. Symptoms we didn’t ignore exactly, but which we paid careless heed of. Until, that is, she asked me one day and out of the blue: “Tell me, when did we first meet?”

Hearing loss has been linked to a higher risk of dementia and cognitive decline, but is preventable with hearing aids, say experts, who recommend testing for a problem which may otherwise go unnoticed

ACB stands for Anticholinergic Cognitive Burden. I only thought to explore anticholinergic drugs, what they are, their effects, and which ones my mother may be—and may have been—on, when a doctor remarked on the dementia risk of sleeping tablets: “Many sleep aids are anticholinergic,” he told me, “that means they disrupt a neurotransmitter in our brain called acetylcholine, which is essential for memory.”

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?

New research shows dementia can be detected via brain imaging 9 years before symptoms start, which gives time to form good habits and hinder its progress

Despite there being no cure, getting a scan and building your brain’s resilience through mental challenges, being social and living healthily will help …

How caring for a parent with dementia taught me about symptoms, prevention and why seeking out the latest research is so important

To many, the word “hobby” signifies something lightweight or trivial. Yet taking on a new hobby as one ages might provide an important defense against dementia, some experts say.

Would today have been better, had I been a better daughter? Dementia Diary: Don’t argue with dementia, a geriatrician told me. They might not remember your name but they’ll remember how you make them feel

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”.