You don't expect eerily accurate prophecy from science fiction. It's especially weird when the work in question comes from the pen of Philip K Dick, a writer with no particular interest in science or the future. But somehow his 1965 novel The Zap Gun anticipates the modern world in a way that nobody else did.
Although people who never read it sometimes assume that it's trying to foretell the future, science fiction is rarely about predictions. More often it gives writers the chance to experimenting with ideas, writing in a realm that gives free rein to the imagination. Sometimes it's laziness. In SF, you can churn out thrillers without any knowledge of how the CIA operates, use detailed exotic locations without ever having been there, and write war stories without any need for historical accuracy. Iain M Banks refers to research as "the R word" and tries to avoid it as far as possible. SF writers can make up pretty much everything in their work, including the science.
In any case, imagined futures invariably look ridiculous long before their due date. Writers are stuck in their own present, and any work they produce will contain elements that look incongruous to later eras. Forties and Fifties SF is always funkily retro; when the space-age husband flies home his jet-car, he will still find his wife baking apple pie in the atomic oven, attended by stereotyped kids. Orwell's 1984, with its bombsites and pervasive smell of cabbage, is perfectly representative of post-war England. And don't even get me started on Star Trek and the Sixties.
Phil K Dick is beginning to be well-known because of film adaptations of his works. Blade Runner, Total Recall, Minority Report, the little-known Impostor and now A Scanner Darkly are all based on his stories. Hollywood likes to use them as pegs to hang action-adventures on, with shoot-outs and punch-ups for the likes of Arnie and Tom Cruise, but the originals have a very different style. Dick wrote ‘inner space' SF, concerned with issues like what it means to be human (Do Androids Dream of Electric Sheep, the basis of Blade Runner), whether you're the still same person if you lose your memory (Total Recall) , and whether it would be just to punish someone for what they will do in the future (Minority Report).