He told BBC today that he started drinking heavily and came close to quitting music altogether after the Beatles disbanded in 1970.
"It was difficult to know what to do after The Beatles. How do you follow that? I was depressed. You would be. You were breaking from your lifelong friends. So I took to the bevvies (drinks)," he told BBC Radio 4's 'Mastertapes' show.
The Beatles, which was also referred to as the Fab Four and included John Lennon, George Harrison and Ringo Starr, officially split in 1970 with the release of 'Let It Be'.
"The business thing split us apart... I was really grateful that we got it back together before he (John Lennon) died. Because it would have been very difficult to deal with if... Well, it was very difficult anyway," said Paul, who was knighted by Queen Elizabeth II in 1997.
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"It was Linda (wife Linda McCartney) who said, 'you've got to get it together...' and that led to Wings. I liked the idea of a band. I wanted to go back to square one," he said.
The episode of 'Mastertapes' will be broadcast on Saturday morning.