My psycho ex-boyfriend used to read me extracts from this book in bed after we'd, ahem, finished. He was obsessed with it. At the time I naively thought he was a bit eccentric. Now I know he was, in fact, a psycho.
I found it really frightening and unpleasant, which is testament to the author's skill. It stayed with me for a long time afterwards. Not sure whether I'd be able to stomach the film