When CBS Corp. CEO Leslie Moonves last addressed the Hollywood Radio and Television Society in September 2006, two events kicked off the discussion: Viacom’s abrupt dismissal of Tom Freston for fumbling the opportunity to acquire MySpace, and Katie Couric’s triumphant debut as anchor of “The CBS Evening News.”

It’s hard to think of two better illustrations that five years has become an eternity in the media business. While Moonves returns to the HRTS Thursday still at CBS’ helm, News Corp. sold MySpace at the fire-sale price of $35 million — about 6% of its acquisition cost — and Couric is preparing to launch a daytime talkshow, what she ought to have done from the beginning.

Still, those examples hardly lack for company, at a moment when it’s easy to feel like we’re living out the Firesign Theatre album (remember those?) titled “Everything You Know Is Wrong.”

The inability to see around fast-approaching corners obviously isn’t confined to media. After all, few political pundits foresaw a first-term senator becoming America’s first minority president in 2008. Moreover, thanks to the Web and cable news, the digital age offers more people making predictions than ever, only with less likelihood of getting anything right — and almost no penalty for being dead wrong.

Nevertheless, the breakneck pace of change complicates everything in media, from simple contracts to labor negotiations, precisely because looking ahead more than a few years is tantamount to flying blind.

Perhaps that’s why some view the current landscape as exciting and others plain gut-churning. It boils down to one’s comfort relying on research, meticulous planning and rigorous analysis versus “Hey, your educated guess is as good as mine.”

Just six years ago, Lachlan Murdoch was the designated “first among equals” in the familial competition to eventually succeed his dad running News Corp. Then he left the company and brother James took the pole position. Now, with the phone-hacking scandal continuing to plague the media titan, it’s increasingly unlikely anyone named Murdoch will be the next CEO.

Far more recently most people would have correctly assessed Oprah Winfrey’s bond with her audience as the most formidable relationship between a particular talent and viewers out there. The convulsions of Winfrey’s joint venture with Discovery, OWN, have tempered those assumptions and reminded us that the margin for error in what might be called “broccoli TV” is razor thin.

As recently as 2007, nobody would have given AMC — American Movie Classics? The channel that always seemed to be airing “Road House”? — a second thought on Emmy night. Now, it’s become the home of some of TV’s most prestigious dramas, including four-peat winner “Mad Men,” reflecting just how quickly fortunes can turn.

A lot of those programs wind up in someone’s DVR queue, by the way, since about 40% of U.S. homes have them, compared to under 10% in 2006. As a consequence, the notion of zapping commercials has become so commonplace that the first glimpse of national ratings offer a highly incomplete picture, with aggregated tune-in for many top shows rising 40% or more over the next week.

Then there’s Netflix, which looked a whole lot smarter and in tune with its customers mere months ago than it does since its public meltdown.

Conventional wisdom certainly isn’t what it used to be.

Granted, people switch jobs and companies suffer reversals all the time, but the sweeping forces reshaping the industry have arguably eclipsed the pace of change in previous decades by a country mile.

If you’re hungry for prognostication, by the way, don’t bother soliciting it from Moonves. Under questioning five years ago from his new morning-show anchor Charlie Rose (and honestly, who saw that coming?), the CBS honcho declined to turn the network’s Eye logo into a crystal ball.

“I learned early on in the television business you never make predictions,” he said.

In terms of not saying something demonstrated to be wildly off almost before it’s out of your mouth, that’s a sound policy. But for anyone thinking about a second career, a word to the wise: It’ll never get you booked on cable news.