“He always thought he had the world’s dullest face, a thoroughly forgettable face … A real conformist’s face, he thought.”

— from the 1955 crime novel “The Talented Mr. Ripley”

Influential Russians must have something in common with Tom Ripley, the sociopathic yet likeable fictional killer who appeared in five books and was later portrayed in movies by the likes of Matt Damon and John Malkovich.

How else to explain why so many members of Donald Trump’s inner circle magically forget they met with Russian government and business leaders?

Here are just a few examples of Russians vanishing from memories among Trump’s team.

• Jared Kushner, Trump’s son-in-law and senior adviser: On a disclosure form related to his request for top-secret security clearance, Kushner was required to note all encounters with foreign government officials over the past seven years. But — poof! — his recollection of a meeting with Russian ambassador Sergey Kislyak in December somehow disappeared. So did meetings with dozens of other foreign leaders and officials. That group includes Sergey Gorkov, who was appointed by Vladimir Putin to head the Russian state-owned bank VneshEconomBank — which has been under sanction by the U.S. for three years for funding spying efforts. In addition, Gorkov received spy training from the Russian academy of Federal Security Service.

• Michael Flynn, former national security adviser: Apparently, the Russians were particularly incapable of making an impression on Flynn. Flynn forgot to mention that he’d sat with Russian President Vladimir Putin during a December 2015 gala, met with Kislyak a year later and had received $30,000 in payments from a state-run Russian broadcaster.

• Jeff Sessions, U.S. attorney general: Sessions met twice with Kislyak during the 2016 presidential campaign, but darned if he didn’t make note of that during his confirmation hearings. It was only after The Washington Post revealed the conversations that Sessions acknowledged them.

• Paul Manafort, former Trump campaign manager: Manafort initially said the so-called Black Ledger — a document indicating he’d received payments from a pro-Russia political party — was fabricated. But then the Associated Press uncovered documents confirming that Manafort received $1.2 million in payments via his consulting firm in the U.S.

There are so many other examples of this stupefying phenomenon, we don’t have room to mention them here. Former Trump campaign aide Carter Page and even Trump himself have either failed to reveal connections with Russians or said they’d forgotten them.

Amazing. Surely, entire teams of scientists have by now started studying this strange anomaly. Let’s call it RFIRS, or Russian Facial Identity Recall Syndrome.

Or, all kidding aside, let’s call it what it is: lying, obfuscating and running scared.

There’s actually nothing humorous about the situation. Americans deserve to know every detail about conversations between Trump’s inner circle and the Russians, given the possible ramifications of those discussions, which include possible sabotaging of our elections and sharing of high-level security details.

Trump has repeatedly asserted that there was no collusion and that he and his team are being subjected to a witch-hunt, but his protests mean absolutely nothing. Trump is a serial liar. His message of “Move along, nothing to see here, folks,” is about as convincing as a patrol cop saying the same thing at a crime scene crawling with investigators and ambulance crews.

Nor should it divert attention from the possible collusion that the U.S.-Russia relationship apparently soured this week over the Tomahawk missile attack on Syria. Just because the Trump administration and the Kremlin aren’t chummy at the moment doesn’t mean there was nothing untoward going on last year.

Missile attack or no missile attack, there’s still more smoke here than in Snoop Dogg’s living room. The situation needs to be investigated with the utmost urgency and aggressiveness.