Paul McCartney (b. 1942) in 1966

On September 23, 1969 – 50 years ago today – the venerable English tabloid the London Daily Mirror reported that Paul McCartney of the Beatles was dead. It was the first time the rumor was printed in the mainstream press.

In 2009, for what was then the 40th anniversary of the moon landing (or was it just a spectacular hoax?), Time Magazine printed a list of 10 of “the world’s most enduring conspiracy theories.” The list is as relevant today as it was 10 years ago, or so I think.

According to Time, the top five conspiracy theories are as follows. At number one is the “Kennedy Assassination”. At number two, the “9/11 Cover-Up”. At number three, and never more relevant than it is today, “Area 51 and the Aliens”. At number four is “PAUL IS DEAD”, and at number five is that “Secret Societies Control the World.” (Okay; one more: at number six is the “Moon Landings Were Faked.”)

I used to giggle about people who believed in crazy “theories” and considered such folks to be essentially harmless. Then I met a “true believer” and I stopped laughing. Between 1999 and 2003, I worked out at a 24-Hour Fitness gym in Walnut Creek, California. There was a very nice, soft-spoken guy – mid-40s, I’d say, with a trim van dyke beard, 6’ tall (or so), in decent shape – with whom I became friendly in the way you become friendly with someone in a gym. He claimed to be a research biologist and I had no reason to doubt him: he was intelligent and extremely articulate. Then one day, while we were sharing a weight machine, he casually mentioned something that made my ears stick up. I asked him if he was joking, and then I heard it all, calmly and logically expressed and without a hint of hysteria, doubt, or embarrassment. According to this self-proclaimed scientist, the earth was some 6000 years old; evolution was a secular lie perpetrated by the Masons (or the Jews, or the Rockefellers and Standard Oil; I honestly don’t remember so gobsmacked was I at this point); the creation story as described in the Old Testament was accurate scientific fact, and that the scientific community as a whole was already drifting in this direction and that within just a few years evolution would be refuted for the ungodly lie that it is.

I was astounded. My initial reaction was that the guy was as whacked as those 39 unfortunate members of “Heaven’s Gate”, the UFO Millenarian religious cult who had not long before committed mass suicide wearing identical black shirts, sweat pants, and brand new black-and-white Nike Decades athletic shoes, convinced – as they were – that this was how they were going to reach and board an extraterrestrial spaceship that was presumed to be following the Hale-Bopp Comet.

So my workout partner was nuts. But no, he wasn’t. But yes, he was. But no, he wasn’t. 

I suddenly understood something I’d never really understood before, and that is that we will – each and every one of us – believe precisely what we choose to believe and, given the right (or wrong) circumstances, we can (and will) convince ourselves of pretty much anything. Under the right (or wrong) circumstances, “reality” becomes friable; “fact” becomes flexible, “common sense” merges with the delusional. I suddenly had an insight into how a great and civilized nation like Germany could, in a time of mass hysteria, embrace a Hitler; how religious extremists, in the name of their “god”, could perpetrate heinous crimes against their fellow people; how governments can keep making the same absurd, misguided, delusional mistakes over and over again. (Though the definition has been improperly attributed to both Benjamin Franklin and Albert Einstein, it still hits the nail on the head: “insanity can be defined as doing the same thing over a...