What’s the most wrongheaded conclusion anyone ever came to concerning computers? I covered three of the most legendary ones–”There is no reason for any individual to have a computer in his home,” “640K should be enough for anybody,” and “I think there is a worldwide market for maybe five computers” in The 25 Most Notable Quotes in Tech History. But there’s no evidence that IBM’s Thomas J. Watson said the first one, Bill Gates staunchly denies saying the second one, and DEC’s Ken Olsen and his defenders contend that the last one is him being taken out of context.

But here are a couple of seriously silly statements that can’t be disowned–because they appeared in columns in the New York Times in the mid-1980s. Both are by the same guy, Erik Sandberg-Diment (who certainly wasn’t always obtuse–he was visionary enough to found ROM, one of the best early magazines about personal computers). Between them, they add up to one of the least accurate takes on the future of computing that I’ve ever read.

Sandberg-Diment’s first memorably inaccurate piece is from Christmas Day, 1984.  It concerned the PC trend of windowing environments–front ends for DOS that let you run multiple apps in windows. He thought they were a fad that had already come and gone–and even spoke of them in the past tense.

Continuing to write about windowing environments as if they had already failed, he declared that they’d make sense only if computers gained displays as big as real desktops. (A quarter century later, a 30-inch screen still counts as humongous–but isn’t anywhere as spacious as a typical office desk.)

Now, it’s true that in late 1984, the best-known windowing environment that had actually shipped was VisiCorp’s Visi On, which was pretty much dead on arrival. Windows, which wouldn’t show up for another eleven months, was famous mostly as an example of vaporware. So Sandberg-Diment was only criticizing windowing as it existed as of the time he wrote his piece, right?

Well, no, he made sure to end his piece by issuing a pre-emptive declaration of “doom” for Microsoft’s Windows.

A little less than a year later, Sandberg-Diment decided that another computing trend had fizzled. This time it was the laptop computer. He noticed that nobody seemed to be carrying the once-hot portable machines anymore, and once again made plentiful use of the past tense in discussing them.

He argued that people didn’t really want to take computers with them everywhere–why would they, when it might cut into valuable newspaper-reading time?

Then he suddenly shifts course and makes a bold prediction: As laptops get cheaper and better, they’d become powerful tools for traveling salespeople and other mobile workers. Popular ones, even!

But just in case anyone thought Sandberg-Diment was a laptop enthusiast, he stated as fact that they’d remain specialty items. No matter how cheap and good they became. After all, who’d want to take one along on–drum roll!–a fishing trip?

After reading this, I did what I usually do when I need a quick reality check of typical computing habits: I turned to Twitter.

A bunch of folks reported back that they had, as I knew they would–these days, there’s no place that people don’t take computers.

Between the two Times pieces, Sandberg-Diment announced that both Windows and laptops were dead. For the record, as of late 2009, the vast majority of computers sold on the planet are…Windows laptops. (As far as I’ve been able to determine, he never wrote a column mocking the notion of online communications.)

The thing is, his conclusions weren’t completely irrational given the information he had at the time: Windowing environments available in 1984 did stink, and laptops were too pricey, bulky, and limited to serve as newspaper substitutes. It’s just that he didn’t have the imagination to see that the issues he saw would get addressed, and that people’s attitudes towards the technologies would shift. He also made the mistake of blithely issuing permanent, blanket rejections of Windows and laptops based on what he could see in 1984 and 1985, rather than being humble enough to acknowledge that computing was likely to evolve in ways he couldn’t possibly imagine.

Why am I bringing all this up now? In part because there’s nothing more entertaining than looking back at hilariously off-base pronouncements about technology. But there’s a lesson in here, too: It’s always a mistake to think you know where the hell technology is going to take us.

At the moment, for instance, some very smart people are utterly positive that Google’s Chrome OS will flop big time. But maybe anyone who’s about to write such a story should be forced to read pieces like Sandberg-Diment’s as a case study in the danger of certitude.