I've been busy with a bunch of other stuff lately, so OGAWA Youko (小川洋子)'s Hakase no ai shita suushiki (『博士の愛した数式』, "The Equation [that] the Professor Loved") took me way longer to read than it ought to. Especially since it's one of those very Japanese stories where everyone is referred to by position or descriptive nickname rather than actual name, and the whole thing verges on parable.

It's got a nice hook, though: the heroine is a maid working for an old mathematics professor who, after an accident in the 70s, became unable to create new long-term memories. So, effectively, his memory is 80 minutes long. Every day he meets the maid anew, then retreats into his study to... study. It's like Memento meets A Beautiful Mind, basically.

The book comes highly recommended. It's won or placed in a bunch of awards -- the democratic kind, where the general public or at least a generous subset thereof gets to vote. I have to admit, though, it didn't grab me the way it apparently did everyone else. Maybe because I already know enough neato mathematics that the stuff in here -- mostly about primes and perfect numbers and other wonders in ℕ, but branching out as far as Euler's identity* -- didn't really come as a revelatory experience. (Ogawa does handle it with style, though, and has since gone on to write another book with a mathematician expanding on the topic.)

Still, it was a fun read, and I got appropriately choked up at the end, and I did appreciate the fact that there were limits to the book's sentimentality and certain things were never unnecessarily clarified.