John's relationship with each of the other Beatles was different. He was at his most relaxed with Ringo, who often had him in stitches with his jokes.

I knew the man up until our divorce - after that I didn't know the man, but it didn't stop me caring about him and worrying because of the complete change that I saw in him. He'd lost his sense of humour and he got aggressive; he wasn't for the world any more, he was just for Yoko. Before that he opened his arms and embraced the world with his wit and humour - afterwards he was a completely different kind of person.

John needed to escape his reality. I understood completely but I couldn't go along with him.

John was closest of all to Paul; their relationship was very complex.

Ringo had this habit of lighting up two cigarettes, one for Maureen at the same time that he lit his own. I remember thinking it was a loving thing to do and wishing John did it for me. But that would have been too obviously demonstrative, maybe, for John.

John was an extraordinary man. Our relationship has shaped much of my life. I have always loved him and never stopped loving him. That’s why I want to tell the real story of the real John – the infuriating, lovable, sometimes cruel, funny, talented and needy man who made such an impact on the world. John believed in the truth and he would want nothing less.

John and I weren't capable of getting back to Kenwood from there, so the four of us sat up for the rest of the night as the walls moved, the plants talked, other people looked like ghouls and time stood still. It was horrific: I hated the lack of control and not knowing what was going on or what would happen next.