A former boss of mine had a saying — perhaps he still says it — that overzealous advocates had a habit of “talking past the sale.”

He meant it to suggest that someone who had a point to make could have stopped trying to make it long ago.

Thus, the president of the United States is “talking past the sale” as it regards a network news broadcast journalist’s erroneous report regarding Michael Flynn’s admission that he lied to the FBI about his contact with Russian government operatives.

ABC News suspended investigative reporter Brian Ross for four weeks without pay after he reported erroneously that Trump instructed Flynn to talk to the Russians while he was running for president; in fact, Trump’s instruction occurred after he was elected, which puts the issue in an entirely different context.

ABC News acted. Ross is off the air for a month — or perhaps longer. The network policed itself. Trump, though, is not letting it go. Oh, no. Now the president is urging “investors” to sue the network for reporting “fake news.”

C’mon, Mr. President! Let … it … go, will ya?

The network has taken ownership of its mistake. However, Ross has given Trump plenty of ammo to keep up his “fake news” barrage against all the media outlets that cover the news — except, of course, Fox News, which caters to the president’s insatiable appetite for “positive news.”

Trump is delivering yet another example of how he doesn’t understand curious relationship between the media and the government. Yes, reporters make mistakes. Some of them are grievous errors, which I consider Ross’s blunder to be.

The president of the United States, though, need not spend a moment more of his time on this matter. He’s got plenty of serious issues on his heaping plate to consume his attention.