The loss of an aunt isn’t one of the big deaths. I told myself that last week. My cousin had emailed with news that her mother, my aunt, had died unexpectedly in the week. She was my mother’s younger sister and lived far away in suburban Johannesburg. I hadn’t spoken to her since November, when I’d called on my birthday. Nothing structural in my life had changed.

And yet it seemed like the most outrageous repositioning of the universe.

My daughters are obsessed with death at the moment, without understanding what it means. A dead bird in the street elicits fascination but no sympathy. On the way to nursery, they stop to regard it like two tiny pathologists. They know my mother is dead and this interests them purely for the forensics. “Do you have a picture of her?” says my daughter.

“Yes, you’ve seen pictures of her.”

“Do you have a picture of her when she was dead?”

“No.” Puzzled pause. “Can we see her dead?” “No.” “Why not?” “That’s not how it works.”

In big families there is often the one who remembers, and my mother remembered everything. She was terrifying at it. She had vast troves of personal data on everyone going back decades – and after her death, I discovered her younger sister had the same tendency. My aunt knew birthdays and divorce dates digging down into the second cousins once removed. She knew the names of the people her seven siblings had dated in high school (in my mother’s case, Derek), or the man their mother had a fling with in the 1960s (Dr Pelkowitz). As each new generation arrived, she accommodated fresh intelligence without jettisoning anything in the archive. It is a curse to remember everything, my mother once said, but she didn’t believe it. Most of us understand that remembering is an act of love.

On news of my aunt’s death, my first thought out of the gate was, I’m sorry. Not sorry she had died; that fact seemed vulgar to address head on, since to be dead is a bit shameful and I knew my aunt wouldn’t like it. I meant I’m sorry things weren’t better. The books hadn’t been balanced. There hadn’t been enough happiness. Perhaps this is the only proper way to feel when someone dies: wanting more.

I don’t know if it is true. She was simultaneously unshockable and extremely judgmental – one of my favourite personality combinations – holding a low opinion of the world which, once confirmed, left her free to go off and be joyful.

I thought of all the things that died with her. Who will remember the significance of Dr Pelkowitz now? It will be too remote to interest my children, as will their great aunt herself. I know this is just how it goes. I stood in our hallway, eavesdropping on my kids as they played and the generations imperceptibly realigned.

“Pretend mummy goes on holiday for 100 years and dies when she’s there and we can do anything we want,” said one, cheerfully, and it was hard not to smile. “OK,” said the other.

• Emma Brockes is a Guardian columnist