Sedgwick’s crime novel set in fin-de-siècle Paris, Mister Memory, explores the implications of remembering everything.

Where did the plot idea come from?

In the early part of the 20th century, the Russian psychologist Alexander Luria studied the case of a man called Solomon Shereshevsky, who had an extraordinary memory. After investigating him for 20 years, he concluded there were no limits to his memory at all, that it was, functionally, infinite. Though he had what seemed an amazing gift, it actually made his life very difficult.

How did you avoid scientific anachronism in your writing?

I was careful when I made my notes to place more emphasis on the older theories and treat the modern views more as points of interest for me, rather than points for the text of my book. To give one example of the way things have changed, the “filing cabinet” model of memory—that we experience something, and then store it away in a memory bank, which we can access later—is somewhat outdated now. The current view holds that each time we remember something, we reconstruct a memory from several different centers of the brain, and that each time we remember it, we construct it anew and possibly slightly differently. Memory, according to the modern experts, is not some fixed and dependable record, but a flexible and frequently untrustworthy tool.

What themes does this book share with your others?

I think the main theme that I’ve addressed elsewhere is obsession. Characters who can’t let go of some thing are the cornerstone of many stories, because they represent the extremes that lie within us all—that we all live in danger of becoming obsessed by something, at times, that we will allow to rule our lives. And, to be honest, obsession is key to a writer because you can’t write a book unless you are yourself obsessed by the story you’re writing. Only obsession will ensure that you sit down in your writing room every day until you have put 100,000 words or so on paper.

Do you approach writing your YA fiction differently?

No. If I was going be provocative, I would argue that writers who do approach writing for young people differently do so at great risk of being patronizing to their audience and producing books that are not very good. In all walks of life, we seem to frequently underestimate young adults: what they are interested in, and capable of, and what they can cope with in a variety of ways. The result is that we patronize them. Is it any wonder then that they stop listening to the adult world and make their own way?