The novel is about a housekeeper who comes to work for a mathematician who has a kind of amnesia where he can't remember things that happened more than 80 minutes earlier. It's a quick read, very simple and pleasant for the most part. I suppose that the amnesia is meant to be the hook, but I loved the book for the math. There are these absolutely gorgeous explanations of various mathematical concepts (some of them, I actually had to stop and think about for awhile to fully understand), and, well, as a child of mathematicians, I'm a sucker for that kind of thing. People talk about the beauty of math all the time, but this is one of those rare books that really makes you SEE it.
Honestly, so far as I'm concerned the rest of the story is actually probably somewhat meh, though it's a pleasing read, but thinking back on it (having finished it all of 5 minutes ago), it's really the math that kept me riveted. Here's an example - the idea of amicable numbers. Amicable numbers are two numbers whose factors add up to each other. For example - 220 and 284 -- 1+2+4+5+10+11+20+22+44+55+110=284 and 1+2+4+71+142=220. Amicable numbers are extremely rare. If that doesn't seem interesting to you (though it should be mentioned that the book sets it into a much more appealing, literary context), well, then maybe this book isn't your cup of tea.
Oh, ps - there's baseball in it too. But I have to say, the baseball part isn't really as compelling as you might want it to be.