Oh, and the book's title stems from the fact that she tries to supply her boy with male role models by repeatedly showing him Akira Kurosawa's "The Seven Samurai".
That, or thereabouts, was enough for me to buy and read the book, but that is not what makes it special. The "special" part is the relationship between mother and son, and the relationship between their little world and the rest of the planet. This latter relationship consists, mainly, of (a) curiosity and (b) contempt, and both are fascinating. The mother, Sibylla, has retained that childlike curiosity for almost everything she doesn't know about - she's perfectly capable of stumbling across a book of, say, the principles of flight, and buy it just because it is so interesting. And this is even more astonishing if you consider that her "job" is sitting at home and typing articles from really boring old magazines into her computer. At the same time, there's a sadness about and contempt for anything that doesn't really live up to her intellect, for the everyday troubles of the "normal" people. The son, Ludo, inherits both - he doesn't know better, and he's in for a big surprise when he gets in touch with others of his age group. (As you can imagine, his time at school is rather burdensome for all participating parties.)
The narrator in the first chapters is Sibylla, but towards the end Ludo gets more and more space for his tales. It's a first-hand view of what the world looks like for him.
Reading this book makes you wonder how many interesting people, how many "great minds", you walk past on the Circle Line each day without even noticing. And - but that's my personal conclusion - it also shows how intelligence and knowledge, but first and foremost not having the knowledge, but longing for it, can make all the difference, even if they're not used to achieve any kind of wealth or status.
This is the best book I've read in the last couple of years. Either buy it now or go away and don't come back. (Chatto & Windus; ISBN 0-701-16956-7, hardcover, ca. 530 pages; paperpack also available.)