Whenever I call my grandmother in the Bahamas I know at the end of the conversation she will tell me how much she loves me.

When I visit I know I’ll find her in her little cottage — where everything is wrapped in plastic and anything else tucked away in aluminium foil — and where she’ll wrap her arms around me and hold me in a warm embrace with sparkling eyes and a smiling face.

But I can’t guarantee she will have a clue who I am.

She does a good job of convincing people that all the lights are still on when the truth is they shine brightly in some rooms (those pre-1980), are on dimmers through the Nineties, while the rooms that contain the last five minutes are well and truly kaput.

Too often the vulnerability of the elderly goes unnoticed because we are too afraid to admit that the guardians who once kept us safe now look to us for security.

When my grandmother tells me stories she often tells the same anecdote twelve times in a row and I her indulge her by giggling in all the right places with the same enthusiasm each round.

My sister has long given up defending herself against accusations of pilfering the cutlery my grandmother buries in her secret drawers and then forgets about.

If anyone is still wondering where Wally, Bin Laden and Elvis are I’m prepared to offer decent odds my grandmother has plunged them into the depths of her hordes and, almost certainly, will never be seen again.

So when I heard Maggie T was suffering from Dementia I felt nothing but empathy for her and her family. Imagining Britain’s first and only female PM helplessly wondering where her dead husband is and not being able to differentiate the Falklands from the Balkans, tugged at my heartstrings.

Having the life you once knew, and the qualities you prized, slowly pulled away from you is, quite simply, a tragedy. But despite one in three people over 65 in this country living with the condition, it often gets passed off as just old age: ignored, undiagnosed and under-funded.

Dementia patients, or their families, are hit by expensive social care bills and denied drugs that could help lift the fog that clouds their memories and could give them some independence back.

That’s not the way to treat those who nurtured us when we were incapable of doing it for ourselves.