He said that he had learned this the hard way after the breakup of his relationship with Paul McCartney, whom he had once regarded as his close friend. John's features hardened as he launched into a terse monologue on the subject. Using his relationship with Paul McCartney as an example, John asserted that most “so-called friendships” were based on a symbiotic exchange of services. “The basis of our friendship was an intuitive understanding we had as musicians,” he said. John explained that when he and Paul first started working together, he needed Paul more than Paul needed him, because in addition to being a well-rounded musician who could help John translate rough ideas into songs, Paul had a secure family background. “Being around Paul gave me a sense of stability,” John said. “When I met Yoko, I knew it was time to cut myself loose. Paul hated me for turning my back on him and did everything he could to turn the others against me. He saw that he couldn't compete with Yoko, so he tried to stab us in the back. He was absolutely vicious, and it shattered whatever illusions I had about our so-called relationship.”