Yesterday a thriller for today

Felicia Yap admits her memory is not as good as it used to be. As a child she had an almost photographic memory, she says, able to remember most things she read.

She went on to study biochemistry at Imperial College London and was a researcher at the European Molecular Biology Laboratory in Heidelberg, before changing course and becoming a Cambridge historian, researching the experiences of people caught up in World War II. Her propensity to retain facts was one of her strong points, she says, helping her through years of study.

But at 36, the author says her memory has definitely started to go downhill. "Somedays I struggle to remember what I did yesterday," she laughs.

Which is the concept for her debut novel, Yesterday. What if you couldn't remember yesterday? Set in a world where there are "monos" who can only remember what happened yesterday, and the superior "duos" who can remember the day before yesterday, Claire, a mono, learns that her husband Mark, a duo, has a mistress who's turned up dead. How can any of them know what's happened, how can the crimes, both the murder and the betrayal be solved?

It's an intriguing thriller. While set in this dystopian future, the storyline is very grounded in the every day. Human emotions are drawn out and dissected as the only way people "remember" things is by filling out their iDiaries, their only link to the past.

Yap was caught up in the characters, in telling the story, when she was writing Yesterday. It was only when she had finished that the theme of the fear of forgetting struck her.

"It's a fear we all have," she says. "We want to remember the past, it's tied to our sense of identity because memories help us craft a sense of self. If you take that away it takes away a part of ourselves."

Yap talks about the increasing rates of diseases such as dementia and Alzheimers, and how more and more younger people are being diagnosed.

"Twenty years ago it was people in their 60s, now its people in their 40s and just recently I read about a 32-year-old had been diagnosed."

But take away this aspect of the story and Yap's treatment of the idea of memory is still a fascinating one. She tells the story from four different perspectives: Clare and Mark, the mistress Sophie, and Hans, the detective investigating the murder

"People remember things very differently," she says."When Claire and Mark begin to excavate their past, their account is quite different. The idea of memory being about what you choose to remember and what you choose to forget is present here."

Much of the story is told through the iDiary entries, as the characters try to piece together what they can of the past.

"When I was writing all the diary entries in the book I made a conscious decision about what facts should go into the diaries," Yap says.

"I realised that emotions make us remember things, each line in this book had to be about things people thought were important, which were deeply connected with strong emotions like love and hatred and how both these things affect memory in turn."

Yap wonders if it's possible to love someone you don't remember?

"I think memory deficiency reduces the capacity for love, that idea was with me when I was writing the story," she says.

"I worked out very early on that hatred could be accumulated, the sum total of grievances can build up but love was trickier to work out."

Born in Kuala Lumpur, her father refilled ATMs with cash and her mother worked as a clerk in a car-repair shop, Yap moved to London in 2000 to study. In 2015 she enrolled in the Faber Academy, an intensive six-month novel writing program whose graduates include S.J. Watson whose best-seller Before I Go to Sleep also touched on the concept of memory.

Indeed Yesterday was pitched as Before I Go to Sleep meets Minority Report, it caused a bidding war among several publishers, and agents fought to represent her. Headline eventually secured it for a six-figure sum. Hollywood is calling, there's a second book, a prequel Today, that she's writing now, and she'd love to write Tomorrow, to tie it all up.

It seems while she's busy remembering yesterday, tomorrow is unfolding before her.

Yesterday, by Felicia Yap. Hachette. $29.99.

This story Yesterday a thriller for today first appeared on The Sydney Morning Herald.