It's because of the abbey road album.
On this Album, Paul didn't wore shoes and fans thought it's like a secret message that Paul is dead and that "other Paul" is like a replacement. And he was holding a cigarette on his right hand but Paul is left handed. In the background, u can see Paul and Linda's car ( the white one ) and there stands "LMW" and the fans thought it were a secret message which means "Linda McCartney widow"
That theory's name is "Paul is dead"
That all happened at 1966 where ppl thought that he got hit by a car

NOOOOOOO
these ppl who think that he's dead r uhh
Kinda stupid??
I mean wtf-

Poor Paul XD

Lol 😂♥️

YEAHHH