“Many people I know in Los Angeles believe that the Sixties ended abruptly on August 9, 1969, ended at the exact moment when word of the murders on Cielo Drive traveled like a brushfire through the community, and in a sense this is true. The tension broke that day. The paranoia was fulfilled.” – Joan Didion, “The White Album”

A lot happened in the summer of 1969, which gives us a lot of 50th anniversaries to mark this summer. We had the moon landing last month, and in June there was the anniversary of the Stonewall riot, which gave birth to the gay liberation movement. You can argue which one changed the world more.

July 19, 1969 was the day Sen. Ted Kennedy drove his car off a bridge on Chappaquiddick Island in Massachusetts and ran to get political advice instead of help for the young woman he left trapped under the water. Woodstock, “Easy Rider” and “Abbey Road” will all get their half-century moment of recognition, but this week the spotlight is on the Manson Family murders.

It’s a story that some people can’t stop retelling – the event that proved that “peace, love and happiness” might really be too good to be true, making the murders a historical punctuation mark that put an end to a season of hope.

I haven’t seen the latest version yet, Quentin Tarantino’s “Once Upon A Time … in Hollywood,” but earlier this year I caught director Mary Harron’s “Charlie Says,” which tells the Manson story from the perspective of his female cult members, and there’s a scene I can’t get out of my head.

It features a character based on Leslie Van Houten, who, under the influence of psychedelic drugs and Manson’s special blend of racism, religion and Dale Carnegie-style persuasion, assisted in the murder of Rosemary LaBianca. 

In the movie, a prison social worker is trying to help her peel back the layers of deception that enabled her and the others to commit such a horrible crime with no sense of guilt.

“We wanted to believe something big was going to happen,” the Van Houten character explains. “I mean, do you remember 1969? It really felt like there was going to be a cosmic shift and things were never going to be the same.”

“It felt that way to most people I know,” the social worker says. “But it didn’t make them kill strangers.”

I think this really shakes me up because I feel that we are living in the middle of one of those big historical moments right now, witnessing events that people will be talking about in 50 or 100 years. Historians will be examining today’s news looking for turning points and missed opportunities. The future we can’t quite make out will be a matter of record for them, and they will judge us on the things we did and didn’t do with information we had.

What are our blind spots? Misreading the historical moment can have tragic results.

The planet is heating up, and doing something about it would require a level of cooperation not seen since World War II. But just when it’s time to act, our democracy is broken. It turns out that some political interests thrive when there’s chaos, and personalized news feeds and big data make it easier than ever to stir it up.

This feels like it won’t end well. 

But I can take some encouragement from the fact that people are notoriously bad at predicting the future. It wasn’t just the Manson Family who believed that the world was getting ready for a “cosmic shift” in the summer of ’69, and they were right. The world has never been the same.

But how many of them were expecting that the change would be a hard shift to the political right? Who predicted that after the victories of the civil rights and peace movements would come decades of reaction, stretching from Ronald Reagan to Donald Trump?

The political lesson from ’69 might be that if something can’t last forever, it won’t. Eventually the tension will break. We can only hope that the paranoia is not fulfilled.