Mum cannot manage the remote control for her television.
Nor can she work the DVD player.
She does not remember what she has seen and what she has not.
Sometimes, she laughs, when I proffer a disc, 'not sure if you've seen this one, Mum?', even though I am and she has; 'Oh put it on anyway', she'll say, 'I'll probably have forgotten what it was about'.
So this evening I suggest The Iron Lady.
Mum looks blank.
I prompt: Margaret Thatcher? First female PM?
Shadows of recollection flicker across her face, as if a veil is being twitched aside, to let the light in: she remembers.
I stick the disc in and press play. We sit and wait.
An addled Maggie shambles onto the screen, bemused, confused, buying a pint of milk.
Mum does not remember this compromised old lady. She remembers her with a spine of steel, a shrill, dictatorial, dismissive, usually disdainful, tone
The waiter stands to the PM's left; what will you have madam? The beef or the chicken?
She considers for a moment, 'the chicken I think'.
And for the vegetables?
She sweeps an arm to indicate her cabinet, seated to eat with her, 'oh, they'll have the same'.
This lady, in headscarf, counting pennies at the till is not that lady.
I explain, 'she sunk into dementia at the end of her life'
Mum looks stricken, 'how awful', she says, 'how dreadful for those whose lives are lost with their memories'.
Do I weep? Do I smile?
I cry quietly a long time later and know I must I be grateful that mum is beginning to forget she cannot remember.