In 1966, Paul McCartney was decapitated in a car accident
He was replaced by a look-alike named William Shears Campbell, aka Billy Shears
Obviously not the same guy, right?
The most common narrative includes the following pieces of evidence: "He didn't notice that the lights had changed" ("A Day in the Life") because he was busy watching the pretty girl on the pavement (the eponymous meter maid of "Lovely Rita") after narrowly missing her dressed in blue (she's said to be the blur on the back of Abbey Road) jaywalking ("Blue Jay Way"). He then crashed into a lamp-post (a car crash sound is heard in "Revolution 9" and "A Day in the Life"). He was pronounced dead on a "Wednesday morning at 5 o'clock as the day begins" ("She's Leaving Home"), and nobody found out this because the news was withheld: "Wednesday morning papers didn't come" ("Lady Madonna").