Predictions about technology's future are almost always doomed. According to 2001: A Space Odyssey, for example, humans should be making flights to the outer reaches of our solar system. Per 1984, by now we should have become a society of brainwashed drones, toiling under constant surveillance for faceless overlords. Clearly, that would never—hey, wait a second!

Nevertheless, Isaac Asimov, the revered science-fiction author, made a stab at describing our lives today—back in 1964. In a New York Times article 50 years ago, Asimov called his vision “Visit to the World's Fair of 2014.” Now it is, in fact, 2014. Shall we dust off his little time capsule and see how well his predictions fared?

You might assume that his projections fall into two categories: the ones that came to pass and those that didn't. Give the guy credit for anticipating self-driving cars, video calling, the widespread use of nuclear power and single-duty household robots. (He didn't exactly name the Roomba, but he did at least propose “robots for gardening work.”)

Asimov also worried at length about overpopulation, estimating the 2014 world population to be 6.5 billion and the U.S. population to reach 350 million. He came very close; the actual world population is about 7.1 billion, and the U.S.'s tally is 317 million.

And, yes, he also got a lot wrong. He foresaw underground and underwater homes becoming popular, along with “transportation that makes the least possible contact with the surface”—cars and boats that levitate on jets of compressed air.

His weirdest prophesies concern our desperate suffering “from the disease of boredom,” once robotics and automation have taken away most of our jobs. “The lucky few who can be involved in creative work of any sort will be the true elite of mankind, for they alone will do more than serve a machine.” If technology ever does buy us more leisure time, technology will also expand to fill it. (A streaming Netflix movie, anyone?)

But many of Asimov's prognostications also fall into a third category that you might not have expected: technologies that are indeed feasible today—but aren't yet commonplace.

By now he thought that windows would be little more than “an archaic touch,” thanks to the popularity of glowing wall panels. Sure, we have flat-screen technology—but we still like to look outside at real grass, sky and squirrels.

In downtown areas, he predicted moving sidewalks. We've built those at airports but skipped them on city streets.

He also figured that our diets would include “processed yeast and algae products” such as “pseudosteak”—an item that might give even tofurkey converts pause. And he foresaw moon colonies established by 2014, with Mars colonies already in the planning stages. In each case, what kept his hopeful prediction from coming true has not been technological; instead we seem to lack the will, desire or courage to make them a reality.

His dream of “large solar-power stations” operating in the desert has been slow to arrive. But stations are finally being built, as economic and political obstacles fall.

Another example: he gives us, the future humans, more credit than we deserve for tackling overpopulation. It must have seemed logical to anticipate “a worldwide propaganda drive in favor of birth control”—but opposition to contraception remains strong.

Asimov's predictions illustrate three lessons for those who would predict the future. First, almost every new technology takes longer to arrive than sci-fi writers imagine.

Second, you'll never hit all the big ones; the history of technology is framed by enormous zigs or zags—consider, for instance, the Internet—that not even Asimov saw coming.

And third, many attractive or logical developments never materialize, thanks to our own human failings. The fault, dear Isaac, is not in our engineering but in ourselves.