I started working at The Washington Post on June 5, 2000. It was in the same building we work in now, but it was very much a different place.

We were just on the cusp between one media age and another, even if not everybody understood that yet. One particularly vivid symbol of the earlier era was this: Every day, sitting in the cafeteria, there was a table of middle-aged deaf men. They sat there all day playing cards, drinking coffee and speaking in sign language.

They were press operators, a colleague explained to me. Against the roar of the old printing presses, being deaf was an advantage; they were unbothered by the noise and could communicate with each other by signing. But the new presses that The Post had recently installed rendered their jobs unnecessary. Protracted negotiations with their union were underway to try to buy them out of their contract. In the meantime, they came to work, clocked in, played cards in the cafeteria all day, and then clocked out.

The year I started, the newspaper division of the Washington Post Company had revenue of $918 million and a 15 percent operating profit margin.  Last year those numbers were $582 million and negative 9 percent. When I started, The Post employed armies of people whose sole job was to man the phone so that we might accept the money people were flinging at us in exchange for the privilege of running classified ads. The idea of a Washington Post not owned by the Graham family was unimaginable.

The old way was unquestionably better for those of us who make a living from media and who enjoyed the job security and paternalistic pensions that resulted. But I’m not going to argue that society was better off. Essentially, every time somebody wanted to sell a used car or rent out an apartment or hire a new accountant in the Washington metropolitan area, we demanded a ransom of a few hundred dollars to place a classified. If you wanted to learn what the president said yesterday or who the Redskins were going to start at tight end, there were only two or three places you could get it.

Now, of course, you can place an advertisement on Craigslist for free to sell your car, read the president’s comments in full at WhiteHouse.gov, and get your Redskins fix from any of numerous local and national sports media outlets. What has been bad for the business of The Washington Post and its employees has been, on balance, good for everyone else who wants to engage in routine commerce or obtain information.

But the changes in media are really one piece of a bigger story. We're in the middle of a wave of technological upheaval in which the different ways information can be transmitted are causing rapid changes in what jobs exist, and how people go about doing them. It affects (or will affect) almost everybody.

Manufacturing workers have spent the last generation becoming accustomed to the rise of robots that do their jobs. But the rapid change is quickly enveloping huge chunks of the white collar workforce. Offices of all varieties have far fewer clerks and secretaries than they did just a generation ago; computers are a lot better at pushing paper than people. Go to a CVS, note the automated checkout machines, and count how many people are working behind the counter compared to a decade ago (and even that's assuming you don't do what I do, and buy your toothpaste from Amazon).

Even in fields that have resisted that dramatic change so far, it seems to be coming. Taxi drivers could come under threat from driverless cars; lawyers are facing the automation or outsourcing of the sort of routine work that pays their bills; college professors may soon find that only the superstars have lucrative jobs in an era of online learning.

This is how economic advancement happens. Nobody argues that the world would be better today if we somehow insisted that the jobs that existed 50 years ago be the same ones that exist today. But what is scary is how fast that change is happening. There is no such thing anymore as a job that you can start as a young person with confidence that you'll be able to keep doing it in more or less the same way for an entire career. For any individual worker, it’s not enough to be good at your job, because there’s a quite good chance that job won’t be around in a decade.

The people who are able to have long and prosperous careers aren’t just the smart and hard-working. It’s also the people who can roll with the punches, be comfortable with change, and adapt what they do to changing technology and circumstance. The capacity for reinvention is something they don't teach in schools, but is the thing that will determine for emerging generations the difference between people who can have a long, successful career and those who will find themselves in a constant career cul-de-sac.

With the sale of The Post to Jeff Bezos announced this week, one of the things that once seemed permanent — ownership of our company by the Graham family — is no more. But the truth is that nothing about doing a job in 21st century America can be permanent, whether it's the technology you use or the ownership. For as long as people keep innovating and creating new, better ways of doing things, permanence, in the business world, is always going to be an illusion. In other words, we're all at risk of being the next deaf guys, playing cards and sipping coffee all day long — except that it's in an age when most of us probably won't get a paycheck for doing so.