The Beatles rocker recalled his feelings of pain after the group's 1970 split in a new interview with British GQ magazine, and spoke of how Yoko and John's criticism cut deeply.
"I remember reading an article, an interview with Yoko, who, OK, she was a big John supporter, I get that, but in this article she goes, 'Paul did nothing. All he ever did was book studio," he says. "And I'm going, 'Err? No...,' " the musician explains.
The pain was compounded after his old bandmate expressed similar sentiments in his track, "How Do You Sleep?"
"And then John does this famous song, How Do You Sleep?, and he's going, 'All you ever did was Yesterday...' And I'm going, 'No, man,' " the "She Loves You" hitmaker adds.
However, he says it's a "misconception" that they all hated each other and that their disputes were more like that between family members. Instead, he blames their then-manager Allen Klein for the bad feeling - even though he found Yoko and John's words "pretty hurtful."
Paul also blames Allen for his decision to sue his old bandmates to dissolve their partnership - claiming he saved the group from themselves as the manager and label executive would have owned their back catalogue had he not won.
"The only way I was given to get us out of that was to do what I did. I said, 'Well, I'll sue Allen Klein,' and I was told I couldn't because he wasn't party to it. 'You've got to sue The Beatles,' " he reveals.
Speaking about the pain it caused him to sue his old pals, he continues, "That was horrendous and it gave me some terrible times. I drank way too much and did too much of everything. And it was crazy, but I knew that was the only thing to do, because there was no way I was going to save it for me, because there was no way I was going to work that hard for all my life and see it all vanish in a puff of smoke."
"I also knew that, if I managed to save it, I would be saving it for them too. Because they were about to give it away. They loved this guy Klein. And I was saying, 'He's a f**king idiot.' "