In his new biography, Many Years From Now, serialised in The Observer's "Life" magazine yesterday, the musician told how he was introduced to cannabis by Bob Dylan, and then two years later gave Jagger his first joint at his London home.
"Funny, because everyone would have thought it would have been the other way around," said McCartney.
The book, due to be published next month, has been written by Barry Miles after hours of interviews with Sir Paul. Speaking of his nightlife in London in 1964, Sir Paul said: "The clubs were all more or less the same: birds and occasionally live music.
"The Bag o'Nails was my favourite. It was supposed to have been a hookers' hangout before, it probably was then too. But young, trendy hookers in miniskirts.
"Now I recall, I might have got asked for money one night after pulling some bird. I wouldn't pay, though, you know."
The book also gives insights into the successful Lennon and McCartney songwriting partnership, how they planned their days and worked together.
Sir Paul claimed he was introduced to pot by Dylan in a New York hotel room in the same year.
"We were kind of proud to have been introduced to pot by Dylan," he said, "that was rather a coup.
"It was like being introduced to meditation and given your mantra by Maharishi. There was a certain status to it."Reuse content