Not many years ago, an ad for a newspaper warned that, “If you miss a day, you miss a lot.”

Now you don’t need a day to miss a lot. Mere seconds of ­inattention can get you behind the curve. What, you didn’t hear about the latest predator to fall on his sword?

The gusher of startling events puts us neck deep in the curse of interesting times. We are in the midst of cultural reckoning over sex, could be on the brink of nuclear war with North Korea and may experience an economic boom as Congress moves closer to historic tax reform.

Then there’s the White House, where the dynamics of upheaval are entering a crucial phase. Although many deplorables believe they finally have a government looking out for them, much of Washington and the American left are preparing to dance on the grave of Donald Trump’s presidency.

Their celebration got an early start Friday with the guilty plea of Gen. Michael Flynn and his pledge to cooperate with special counsel Robert Mueller. The news persuaded James Comey, the insufferably self-righteous former FBI boss, and the Democratic media that the clock is ticking on Trump’s time in the Oval Office.

That is one way to look at Flynn — if you assume he has beans to spill. He was close to Trump but it’s worth noting that Flynn pled guilty to a single count of lying to the FBI, including about a phone conversation he had with a Russian official last Dec. 29 — seven weeks after the election.

That’s the same call that got Flynn fired after less than a month as Trump’s national security adviser because he lied to the vice president about whether the conversation covered sanctions.

So it’s clear that Flynn is a serial liar, but decidedly unclear whether he knows anything that would put Trump in jeopardy. It’s important that the content of his conversations with Russians are not the ­basis of his admitted crime and do not appear to be illegal.

No collusion ,” Trump said Saturday. “There was absolutely no collusion. So we are very happy.”

Happy seems a stretch, but it is a fact that the probe into whether Trump’s campaign worked with Russia to alter the election has found zero evidence so far. Four Trump associates have been charged, but no count relates ­directly to the probe’s original purpose.

That’s not to say Trump is innocent of the damage to his presidency. If nothing else, he is guilty of terrible judgment in the hiring decisions that led to this morass.

An outsider with no government-in-waiting, Trump had few good options and no experience building a campaign. As a result, he created his own swamp.

Besides Flynn, Trump hired Paul Manafort, a lobbyist with less than a sterling reputation, and made him campaign chairman for ­several months.

Manafort and his business partner, Rick Gates, who followed him to the campaign, were indicted by Mueller on charges of money-laundering and making false statements tied to their previous work for a Russian-leaning political party in Ukraine.

The fourth person charged, George Papadopoulos, an adviser to Trump’s campaign, has admitted lying to the FBI about attempts to set up meetings with Russians.

Papadopoulos was a minor player, but there is a curious timing element to his crime that could be significant to Mueller. As a former prosecutor pointed out to me, Papadopoulos admitted he lied to the FBI last Jan. 27, when Comey was still director.

That same day, Comey got a call from Trump inviting him to dinner at the White House that night, Comey told Congress.

Comey testified that, with the two of them alone, Trump said he expected “loyalty.” Comey said he promised “honesty.”

The former prosecutor I talked to points to that day and believes it’s likely that Papadopoulos alerted the White House about his FBI interview, and that could ­explain Trump’s sudden invitation to dinner.

If so, the theory goes, Mueller is exploring a possible obstruction-of-justice charge against Trump, which is what Comey has pushed for ever since he was fired by the president. It is why Comey, acting like J. Edgar Hoover, leaked his notes about meetings with Trump, hoping it would lead to a special counsel.

He got his way, and got a bonus when his friend and colleague Mueller got the job.

Those events led the former prosecutor I spoke with to conclude that Mueller is climbing the ladder, charging people with any crime he can find to get their cooperation for the next rung. He believes Trump son-in-law Jared Kushner is next on Mueller’s list, adding: “They’re all f–ked, they’re all going to be indicted and we’re going to end up with a constitutional crisis.”

That makes two assumptions: Kushner is legally vulnerable on some issue, and has knowledge of collusion or obstruction.

Even if the first part is true, it doesn’t mean the second is. Besides, what would collusion look like? And if there was no collusion, how could justice be obstructed? Most important, would any of that be sufficient grounds for impeachment?

For now, Mueller’s methods seem an awfully slim thread on which to hang a presidency. Trump won the election by a convincing margin and Mueller, who has conflicts of interest up the ­gazoo, has become a political force outside the political system. ­Nobody elected him, but he’s now the decider.

Meanwhile, Trump’s presidency is a work in progress, but there is progress. Only a fool (or The New York Times) would deny that his push for economic growth is largely responsible for the surge that has seen the Dow Jones average climbing by more than 30 percent since the election.

It’s not just the stock market. Jobs, jobs, jobs are being created, with the unemployment rate of 4.1 percent the lowest since 2000. Business and consumer sentiment are soaring.

And if the Senate and House resolve their differences on taxes, growth is likely to keep expanding, with more jobs creating more opportunity for more Americans.

Yet Mueller’s probe is a threat to all that just by its existence. For example, early reports of Flynn’s guilty plea sent stocks crashing Friday as the Dow fell 283 points in eight minutes. It gained most of it back but settled down 41 points on a day when it was poised to climb higher over the tax bill’s progress.

Then again, the roller-coaster day traces back to yet another Trump hiring mistake, this one his biggest: making Jeff Sessions attorney general.

Sessions’ decision to recuse himself from everything related to the campaign led to Mueller’s appointment. Had Sessions done the honorable thing and declined the AG job, Trump could have put someone else there and Mueller would still be in private practice.

Instead, we are where we are, careening between progress and disaster, with no end in sight.