On Friday, November 22, 1963, the United States of America lost its 35th President. But it gained much more. A new way of viewing the world.
JFK's true legacy is that his death heralded the first time a conspiracy theory passed from being the remit only of fanatical crack-pots, and transformed itself - seemingly overnight - into a plausible form of popular knowledge.
It was because of Kennedy's death in Dallas that the conspiracy theory was born. And it all started with an article by American attorney, Mark Lane, potently titled: Defence Brief for Oswald. After this article appeared in the National Guardian, allegations of conflicting theories of events involving obfuscation and deception at high levels of power unfolded. And it was this knowledge of alternative strands of evidence and events that filtered its way into popular consciousness.
It changed everything.
Before JFK's death people were happy to watch I Love Lucy, The Ed Sullivan Show, and The Seven Year Itch. After JFK, a generation was born that demanded shows like X-Files and Alias, with their convoluted plots and mysterious cigar-smoking men in corridors of power. Dan Brown made a fortune out of The Da Vinci Code. And nothing was taken at face value again.
The post-1963 generation is comfortable asking questions such as who killed the electric car and did the Royal Family order the assassination of Princess Diana, simply because the groundwork was laid out for us in the events of 1963. Conspiracy theories have become a part of the normal fabric of life, and anything is a target from moon landings, immunisation, to toxic "chemtrails" from planes. It's never ending.
I'm not saying there is any harm in questioning authority. It signals a healthy democracy. This year, left-wing activist John Minto said he had dismissed the threat of the Government Communications Security Bureau's expanded powers under the GCSB Bill as a "conspiracy theory" - that was - until it was found the GCSB had already been spying on 88 New Zealanders. But conspiracy theories can lead to uncertainty. And the post-JFK generation live in an era where they don't know who or what to trust. Humans have survived in this world because we have evolved the ability to connect random dots in a way that allows us to make sense of our universe.
It is our ability to link ideas and thoughts together in complex ways that make us who we are. This type of thinking is hardwired into us.
According to Michael Shermer, author of The Believing Brain, humans are governed by "patternicity", which is the ability to find "meaningful patterns in meaningless noise".
But in today's world when there are just so many dots out there that can be joined in random ways, it is hard to know what to believe. And Shermer says we don't have a built-in "baloney-detection" device to tell us what patterns we should believe and those we should dismiss as random occurrence.
And that's the problem.
It's easy to become paralysed with indecision spawned from chasing conspiracies, which is as productive as chasing rainbows. At some level you have to be able to say "enough is enough", and learn to take things at face value.
JFK was shot. He died. The world moves on.
We adapt to life's changes or we don't. It's as simple as that. If you want to spend your life hunting for conspiracy theories behind every door you're going to find them. But is that how you want to live your life?
• Dana Wensley has a PhD in medical law and ethics from King's College, London.