My Dad is getting more forgetful. True, he has just made his 95^th birthday but like that stain that slowly spreads into “a gigantic ace of hearts” at the murderous climax of Hardy’s Tess of the D’Urbervilles, there is a growing realisation among family members that this is a bit more than a run-of-the-mill absentmindedness.

Do we vanish with our memories? I’ve been repeatedly reminded, in judging a poetry competition recently, how much poetry depends on remembering, how much any of us depend on memory for a sense of who we are. So perhaps memory is a candidate for what makes us distinctly human – better even than language, the uniqueness of which has been challenged the more we understand of the animal kingdom (See Christine Kenneally’s book, The First Word)? Recalling moments from our own lives – Wordsworth’s “spots of time” that retain, he believes,  a “renovating virtue“ – seems to have something to do with identity, mental health, even our own ethical behaviour: they shall not be forgotten, we have been saying a lot recently.

A few months ago, I read a Guardian piece about nostalgia and have kept a copy of it with me since. Nostalgia as a term was coined by a 17th-century Swiss army physician who traced the fragile mental and physical health of his troops to their longing for home – nostos in Greek means home and algos is the pain they found in such thoughts. So its roots are in mental disorder or depressive illness and for centuries it has been considered unhealthy to dwell in this way on the past, a yearning for something lost, a debilitating rosy-tinted malady.

But psychologists have started to think of nostalgia as a more profoundly rooting experience, even a stimulant to optimism, to psychic health. At Southampton University, Constantine Sedikides and Tim Wildschut have shown the universality of nostalgia and, among its measurable effects, it is now seen as a driver of empathy and social connectedness, an antidote to loneliness and alienation. Nostalgia, by connecting our past and present, by proving the temporal oneness of being, points optimistically to the future, acts to protect against negative thoughts and situations.

The article quotes Wildschut: “Nostalgia compensates for . . . feelings of meaninglessness or discontinuity between past and present . . . it elevates meaningfulness, connectedness and continuity.” Anecdotal evidence comes from women in concentration camps who “responded to starvation by waxing nostalgic about shared meals with their families and arguing about recipes”. This is a sort of imaginative “as if” loop that writers will readily recognise and evidence suggests it can temporarily affect our body states.  Concentration camp survivors recount: “We used our memories to temporarily alter our perception of the state we were in. It was not a solution, but the temporary change in perception allowed you to persevere.”

Remembering our past serves to remind us of who we are, what we have been, what intimacy we have achieved, what we are capable of, then and now, in the future. It builds resilience because, though often concerned with trauma and sadness, it is posed in a redemptive sequence: ‘look we have come through’ cries D H Lawrence and even Larkin’s depressed-sounding “first boredom then fear” might be read in this light. As to ethical consequences, apparently, in strongly nostalgic states individuals are more liable to act altruistically; the value of money is weakened; couples and families bond more closely; gratitude and connectedness increase; children grow less selfish.

Meagre comfort when it’s you, or your father, losing the ability to recall; really this makes the loss of memory associated with old age that much more devastating. But at Southampton they are investigating nostalgia-based therapies for illnesses, including clinical depression and perhaps Alzheimer’s. Robert Lowell somewhere talks of the Christian trinity of God, Son and Holy Ghost, being replaced in the 20^th century by Dad, Mum and memories of my family. Perhaps now we are gathering scientific evidence (if it was ever needed) that such a shift in focus was as much gain as loss. My poem ‘Four trees fallen’ (from The Time We Turned (Shearsman, 2014)) recollects the observation of trees fallen, the roots up-turned an image intended to evoke the unearthing of past experience:

this tree up-turned

with its metres-wide plate

of spreading roots tipped fully

ninety degrees from the horizontal

so what lay underground

is now exposed to the air [. . .]

I imagine it must have been

this same wind though perhaps

in the tempestuous pitch

of night that blew with such power

to topple a tree like this

to lever its roots up-turned

from almost immemorial dark

into the temporary dark

of one night’s storm—if it was

at night—left exposed at dawn

to new sunlight to noon and sunset

The final section remembers a pair of those fallen trees you sometimes come across where people have hammered coins into the rotting bark – a form of payment perhaps, but what for? A journey we hope always to be able to make.

Walking on—and with each step

I remember a third fallen tree

this morning this one skirted

some miles back beside a stream

yet this other trunk bristled

weirdly with half-moons of coins

in its papery folds each hammered

by walkers till the coins were bent

and stressed from blows

of rocks needed to sink them deep

and this tree I also remember

was not the first of its kind—what

year was it what walk beside

what stream of whisky-brown waters

did I stand by a fourth fallen trunk

in that same way gleamingly

scaled with hundreds of coins—

some had planted light-hearted

coppers while others had

invested more heavily with silver

or the thick edges of pounds

and even two-pound coins—

I suppose just taking a breather

or something to amuse the kids

while others thought playfully

to placate the spirits of the place

with its damps and shades

and slippery rocks—perhaps to give

a gift that could never be spent

digging deep in their pockets

as I too hammered and thought

I might pay the fare for a journey

yet to be made to find my way

back to dispense with the need

for daylight tempests or storms

in the pitch of night to retrace

my steps to the original place

whether it might be noon or dusk

or rain or shine a decisive taking

back a preternatural reprise