Recently I gave an interview about one of my favorite career projects, Carmen Sandiego. It was being researched by an archivist! I hadn’t been asked in years about the mysterious thief in the red trench coat and fedora. As big as she was in my life and on the national stage, save for a new motion picture in development, few people remember dear Carmen as much more than nostalgia. For that matter, who remembers the massive multimedia magic of CD-ROM computer games with all of 700mb of storage?

There she is. There she isn’t. Nothing lasts forever. Very little lasts long at all. That is the stuff of our culture. That is the stuff of our careers. Hold on too tightly to anything and you find yourself grasping ancient pixel dust.

Creative destruction is increasingly real and accelerating faster than ever. A new company comes, an old company goes. Brands emerge and evaporate before our eyes. In the start-up world, the notion of permanence is almost impossible to envision. Look forward with alacrity or don’t bother looking up from abandonment.

Contemporary taste is fickle. Technology trends are more fickle. Customer loyalty is most fickle.

Earlier this year I watched the National Geographic Channel limited series Valley of the Boom. I couldn’t tell if it was a dark walk down memory lane or an idealist’s time capsule of lost promise. Netscape—the big bang of the internet age—went from conception to extinction in all of about four years. The Globe—the biggest IPO of its time—was practically eviscerated at birth. Pixelon—a scam extraordinaire foiled by its own iBash—today doesn’t even make a decent trivia question on a game show.

Those were just three emblematic stories, real-world cautionary tales of boom and bust. You might remember the history of other exploded rockets, from Pets.com to Webvan. Maybe you don’t want to remember. Of the big consumer-facing internet companies that emerged from dotcom v1.0, it seems Amazon, Priceline, and eBay are the only lauded brands continuing to operate at large scale.

Google emerged in the second wave of the internet, capitalizing on all the failed portals’ inability to understand the essential nature of search, most notably the excruciating death spiral of Yahoo. Can you think of another important round-one bubble survivor? Which will be the next to vaporize? Jeff Bezos has already said Amazon won’t last forever. He knows inescapably it will be replaced by something fast moving and better.

Today there are reportedly 300 or so companies affectionately refered to as “unicorns.” These are start-ups largely in the technology sector with a valuation of more than one billion dollars regardless of revenue or earnings to justify the bragging rights. You are undoubtedly familiar with many of their quirky names: Uber, Lyft, WeWork, Airbnb, DoorDash, Slack, Pinterest, Instacart… these are widely regarded as some of the good ones.

How many of these brands will today’s schoolchildren recognize when they become adult consumers? You know they won’t all still be around. History assures us of that—unless of course this time is different (and when someone tells you this time is different, keep your hands on your wallet).

Early last year I wrote an article titled Is Facebook the Next AOL? At the time I wasn’t sure. Later in the year I wrote about it again. By then Mark Zuckerberg had testified before Congress and I had become sure. Facebook is going to fall hard. The level of cynicism over there is no different from the hubris of America Online. Today cash is pouring in and it has no serious competitors, so hey, it must be invincible, a forever brand!

Facebook only has one major problem corroding its innards: customers don’t trust the people running it. No product or service can last long that way. It’s hard to be a forever brand when your promise is held in contempt. You can pay lip service to addressing the failings in your business model, but if the core concept is fundamentally conflicted, you can’t beat the reaper.

Even General Electric has fallen from grace. GE, the one original Dow Jones industrial average company dating back a century, is no longer in the Dow 30 index. How can that be? Yes, it is still an enormous enterprise, too big to fail, one might say. Does that mean the brand matters a fraction as much as it did a decade or two ago?

Nothing lasts. Creative destruction is consistent that way.

Google will last a long time because it has built a mighty moat, but it won’t last forever.

Apple? Depends on how it deploys its seismic war chest of cash.

Netflix? Hard to imagine, but it seems like a transitional platform. It could be bumped off.

Microsoft is evolving again, truly embracing the cloud, so maybe it will be the new GE. It has lots of runway to continue reinventing itself, but like GE, no runway is infinite.

What’s the point? Think about your own Carmen Sandiego, that gig you love that will be gone someday, and plan your career accordingly. Are you ready to lose the inevitable and discover what comes next? The ship you are on may appear to be built out of steel, but steel eventually rusts. Are you looking beyond the bow?

Creative destruction wins every single time, but don’t despair. Where old jobs become obsolete with antiquated value propositions, new jobs emerge requiring fresh ways of looking at the world. I doubt that will change. While so many companies have come and gone in the last quarter century, the planet has lifted two billion people out of abject poverty. There are new pockets of middle-class workers emerging all over the world in an increasingly shared global economy. That seems like a decent enough tradeoff for a few trampled unicorns.

Maybe someone will even capture Carmen Sandiego. You never know what can happen when you let go of everything you don’t need anymore.