The four-piece played to a screaming crowd at Candlestick Park in San Francisco in 1966, their last big concert.
Ahead of the world premiere of a film documenting their touring years, Sir Paul and Ringo Starr recalled the manic period in their careers.
In conversation with comedian and fellow Liverpudlian John Bishop, Sir Paul told The One Show: “I think I was the last to give in.
“We did Candlestick Park and it was OK, a lot of screaming and we didn’t enjoy the gig and we were just hustled into this meat wagon which was just like a chrome box and we are all just sliding around looking at each other thinking ‘bloody hell’.”
Starr, who will join Sir Paul in London for a screening of Eight Days A Week on Thursday, added: “We had just had enough, we knew that was the last gig, it was time you can only do that for so long.”
The Fab Four performed their final live gig on a rooftop in London three years later.
Coping with their meteoric rise to fame was made easier by the fact the foursome could rely on each other, said Starr.
“We had each other to hold on to,” he said during the interview at Abbey Road Studios. ” At different parts in our career we each went mad and we had the other three to say ‘are you kiddin’?’ and bring us back. I love that.
“I’m an only child and suddenly I had three brothers, who cared and looked out for me and looked out for each other, and I felt sorry for Elvis, he was all alone.”
Eight Days A Week – The Touring Years is directed by the Oscar-winning Ron Howard.