Researcher William Hirst, of the New School for Social Research, conducted a long-term study of the memories of victims of the Sept. 11 terrorist attacks.

His finding: People’s remembrances of that dark day are not as reliable as one might believe. “Flashbulb memories’’ formed by upsetting events, he wrote, are often wrong.

Hirst and his researchers followed more than 3,000 participants over a 10-year period. They found that, over time, many forgot key details of the attacks, while others had false memories involving events that did not happen.

Yet most surveyed remained confident in the accuracy of their 9/11 memories, even as the consistency of those memories declined with time.

Which leads us to Christine Blasey Ford, who claims that Brett Kavanaugh, nominee for the Supreme Court, assaulted her roughly 36 years ago. He denies it, even saying he wasn’t at the party she describes.

The #MeToo movement demands that we believe the accuser. But one can believe something traumatic happened to Ford without necessarily believing it happened the way she describes.

And should one flashbulb memory really sink someone’s career?

In a letter to Sen. Dianne Feinstein (D-Calif.), Ford describes a party that happened when she was a student at the all-girls Holton-Arms School in Bethesda, Md., perhaps in 1982. Kavanaugh would have been about 17, at the end of his junior year at the all-boys Georgetown Preparatory School.

Kavanaugh and his friend Mark Judge, she says, were drunk and took her into a room. While Judge watched, Kavanaugh allegedly pinned her to a bed and groped her over her clothes, grinding his body against hers and clumsily attempting to pull off her one-piece bathing suit.

When she tried to scream, she claimed, Kavanaugh put his hand over her mouth.

“I thought he might inadvertently kill me,” Ford told The Washington Post.

Finally, Judge jumped on top of both of them, the group tumbled to the floor and Ford fled.

Ford did not tell anyone about this until 2012, when she spoke of it in couples therapy with her husband.

This therapy apparently convinced her that the incident had given her anxiety and PTSD. “I think it derailed me substantially for four or five years,” she told the Post, and hurt her relationships with men.

How much did therapy shape the memory Ford now tells?

We don’t know what happened in 1982. Judge Kavanaugh denies the incident occurred. Kavanaugh reportedly told one senator that he thinks Ford may have mixed him up with someone else.

If Kavanaugh and Ford are brought back in for questioning, it will come down to he said/she said.

Kavanaugh should be judged by his judicial skill, and perhaps by his political views, but not by the recollections of one. Memories can lie.