It can be the smallest thing that sets you off. The smell of bacon frying, or the theme tune to Match of the Day. For Rachael Prior, it was a bright red M&S jumper.
Picking up the cosy knit in the menswear department, Rachael experienced a sudden wave of grief for her late father, Lynton, who had died 10 years earlier. "I'd have picked it for him and I could imagine his face in that moment," she told the BBC.
She posted on Twitter: "Nowhere and no time do I miss my dad more acutely than in the men's department of M&S at Christmas".
Nowhere and no time do I miss my dad more acutely than in the men’s department of M&S at Christmas.— Rachael Prior (@ORachaelO) November 11, 2017
It quickly went viral, with over 2000 people commenting on it with their own stories of the little things which can trigger a wave of sadness at this time of year.
J K Rowling, Alison Moyet and James Corden were among the more famous names to retweet and share their own stories.
Singer Moyet wrote:
I played Southend tonight. Every time I have I was stressed because my parents were in the audience.— Alison Moyet (@AlisonMoyet) November 11, 2017
This time I was aware that they were not.
Corden shared the thread, saying: "It will warm your heart. Beautiful"
Meanwhile JK Rowling joined in, saying the outpouring of memories showed how "Twitter really is wonderful sometimes".
Rachael's tweet was seen by people who had been taught by her schoolteacher dad years ago, with many of them sharing moving anecdotes about him.
Read this whole thread and it will warm your heart. Beautiful x https://t.co/cGV0g52e0h— James Corden (@JKCorden) November 11, 2017
One wrote: "I had the time of my life at that school, it was everything that a primary school should be. Your dad was a huge part of that. Also, his assemblies were legendary. He was a lovely, lovely man."
People also shared their own experiences, with many citing the smell of aftershave, tea or tobacco as the thing that always triggers them to remember a loved one.
It’ll be five years in December. The last thing he ever said to me and in his handwriting. I carry his love everyday ❤️ pic.twitter.com/PaQNT0WVUL— Let It Bri (@realslimchicken) November 11, 2017
Rachael told the BBC: "It was nice to share my moment. Twitter has felt like a place overwhelmed by politics of hate, so this thread reminded me why I joined. It can be a place where people come together and support each other.
"Everyone can connect to the loss of a loved one."