There's this song by Wall of Voodoo called ''Far Side of Crazy'', go listen to that a few times then come back and read the rest of the comment.
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pretty cool song right?
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Anyway, It's about John Hinckley, a lot of the lyrics were lifted from a sort of manafesto he wrote, he tried to assassinate Ronald Regan, he had a lot of mental health issues, and he watched Taxi Driver, and decided to do what he titular character does in the film by assassinating a politician, it's not clear if he understood Jodie Foster was a seperate person from the character she played in the film, but his motivation was to impress her.
Anyone who knows who Hickley was historically, as he was released recently, and there's video of Regan doing his 'missed me' joke at rallies making it's rounds ever few months, I'd say pretty much anyone with internet or reads the newspaper likely knows.