I met an old friend from high school once who had experienced a traumatic head injury – we rode horses at the same place. She had almost photographic recall of long term memories from high school, but almost no short memory. Every time we encountered each other it was as if we were meeting for the first time after many years, and we would often cover the same territory in discussion – remembering our highs school days. The Housekeeper and the Professor by Yoko Ogawa reminded me of that time. The story is a sweet domestic drama set in Japan.

A problem isn’t finished just because you’ve found the right answer.

A housekeeper who is single mother to a young boy is placed by an employment agency with a new client. He is an old man who lives in a two room apartment at the back of his sister-in-laws house. The professor is a brilliant mathematician who’s short term memory only lasts 80 minutes after a traumatic head injury in a car accident. Pinned all over his suit are reminder notes he has written to himself to try and remember things that matter. The disability has not interfered with his ability to solve complex mathematical problems. 

Solving a problem for which you know there’s an answer is like climbing a mountain with a guide, along a trail someone else has laid. In mathematics, the truth is somewhere out there in a place no one knows, beyond all the beaten paths. And it’s not always at the top of the mountain. It might be in a crack on the smoothest cliff or somewhere deep in the valley.

The professor asks the housekeeper for her phone number and shoe size and explains the significant of those numbers, then draws a picture of her and pins it to his jacket.

Soon after I began working for the Professor, I realized that he talked about numbers whenever he was unsure of what to say or do. Numbers were also his way of reaching out to the world. They were safe, a source of comfort.

One day the housekeeper has to take her son to work with her and he and the professor become friends. He calls the boy Root, after the square root sign, because the top of his head is flat. They bond over baseball and maths homework.

He treated Root exactly as he treated prime numbers. For him, primes were the base on which all other natural numbers relied; and children were the foundation of everything worthwhile in the adult world

The Housekeeper and the Professor is an study of number theory – prime numbers, triangular numbers, amicable numbers – and a gentle exploration of relationships without memory.