Sometimes a guy with an umbrella is just a guy with an umbrella.
a short film by JFK assassination researcher Errol Morris, who will no doubt frustrate conspiracy theorists by pointing out that the real world is a lot more complicated, interesting, and bizarre than it seems. His main contention is that if you look closely enough at any event, you will start noticing a lot of "really weird" stuff, but that most things have a perfectly rational explanation if you listen.
On that fateful morning in Dallas, it had rained the night before, but it was sunny and 66 degrees as the motorcade entered Dealey Plaza. No one in the footage is dressed for rain… except for one man, who was standing beneath a black umbrella. Coincidence piles atop coincidence: he happened to be standing beside the freeway sign, exactly where the car passed as the shots began to be fired. Almost as if his position was the signal to start firing.
In 1978 the Umbrella Man came forward and testified before a House committee. He testified that the umbrella was a protest of JFK's father, who was in favor of appeasing Adolph Hitler before WWII. The umbrella was a reference to Neville Chamberlain, Britain's pro-appeasement Prime Minister, who famously carried a black umbrella as a fashion statement.
As Morris points out, this explanation is just bizarre and nonsensical enough to be true. Who would concoct such a patently foolish story? If you were actually signaling the assassination, wouldn't you say something more sensible, like "I was shielding my eyes from the sun"?
The real problem here is that we have been conditioned, through hundreds of thousands of hours of watching movies and television shows, to be alert to the quirks of narrative. On TV, if a character mentions that they have a headache, it's never a headache - it's brain cancer, which will prove fatal in the third act. If a coffee cup is found out of place in a movie, it's because a poltergeist put it there, or it was moved by a thief, or some other such dramatic explanation.
In reality, people get headaches, coffee cups get put in odd places, and people sometimes stand around waving umbrellas for really dumb reasons. Reality is messy and has a poor sense of narrative flow. That's why humanity invented stories in the first place - to bring order to the chaos that envelops our lives. But this also makes it hard to step back sometimes and see that sometimes a guy with an umbrella is just a guy with an umbrella.