We don't talk enough about why our old photos matter –but they do. This is why…

My beloved Nana died from dementia in June, less than two weeks before she would have turned 99. Her last five years had seen her lose the use of her legs, motor skills and voice – and finally, fatally, her ability to swallow food and drink.

Although I'd had years to come to terms with the fact she was dying, I was floored and depressed by her death. My favorite member of my family, she'd been kind and loving with a hilarious sense of humor. She had been around for my whole life, and I couldn't process the fact that she wasn't anymore.

Of Iranian-Indian heritage, Nana had been stunning – a beauty queen in her hometown of Nairobi, Kenya. Last year, on her 98th birthday, my aunt had baked an amazing cake with a topper featuring a photograph of Nana in her prime. She had been so beautiful in an elegant off-the-shoulder 1950s dress, yet 70 years on she stared blankly at the walls of the care home, unable to focus on the photograph.

For the funeral, my mother asked me to send my aunt pictures of Nana. I only had a single photo before she went into care. Taken on Nana's 84th birthday by a photographer friend of mine who owned a DSLR, it's a nice picture, but not a particularly emotive one – Nana looks a bit bored.

The funeral took place on what would have been Nana's 99th birthday. I was dreading it but, thanks to photography, it turned out to be a wonderful celebration of her life. My cousin had put together a slideshow of mostly black-and-white photos of Nana, the majority taken when she was young in the 1940s and 1950s. I have no idea who took them or by which method, but it was a real joy to see her as such a happy, fun-loving young woman.

We saw Nana in white sari and long black gloves on my grandfather Papa's arm, looking for all the world like a Persian Audrey Hepburn. Ever the loving husband, we saw him dancing proudly with her, looking like the cat who got the cream. We saw Nana as a smiling beauty and a teenage ballerina, lithe and poised. There was even a funny photo of her crashed out asleep at a party, surrounded by balloons!

I asked my cousin for the photos and he shared the Google Drive link. The photos were labelled with generic filenames, so I relabelled them more evocatively, like 'Nana Audrey Hepburn' and 'Ballerina Nana'. I am planning to order four prints of them for my room.

I only have 14 folders on my desktop – and Nana's photos are now in their own folder. Every time I need a pick-me-up, I open it and smile, seeing my charming and mischievous Nana full of joie de vivre, having a brilliant time in her youth. Dementia sucked all the pleasure and hope from her existence, but the photos are a much-needed reminder that she'd led an incredible life.

Check our guide to the best photo scanners to avoid reflections when you take pics of your old photo prints.