Just like a toddler understands another toddler and a drunk understands another drunk, a crazy person understands another crazy person. The author obviously wasn't too sane when he wrote it, so, if you think yourself as sane, don't read it. But if you think you're (more than a little) crazy, like sci-fi and like to laugh, you'll love it.
It has no point, for the most part makes no sense and the things depicted in it are only likely to happen if you have the Improbability Drive on... But it's great. As I said, unless you think of yourselves as being sane, it's a great read.