Paul wanted to record a new album and film, but John was uninterested and using heroin. Paul wanted rigorous rehearsals for perfection like Simon and Garfunkel, which John and George disliked as they saw themselves as adults. John found the filming at Twickenham studios a dreadful experience. They left Glyn Johns to edit hours of tapes alone. Phil Spector later edited the sessions, which had many takes due to Paul's desire for rehearsal. They quickly made Abbey Road to preserve their image, and Paul released his solo album to show he was still important to the Beatles. John hoped his new album would motivate Paul to make great music again.

1. John talks about the album ‘Let It Be’ (page 100 in the book):
The album came about because Paul said it was time to do something, a
record or film. John didn’t give a sh*t and was stoned all the time on heroin.
Paul had the idea to rehearse the songs and go for ‘perfection’ a la Simon
and Garfunkel, and John and George didn’t go for that, they were adults.
John says it was a dreadful feeling being in Twickenham studios with the
filming going on. They let Glyn Johns edit the tapes and just said : Here, do
it. None of them could be bothered going in to work on the music. They would
each get an acetate and discuss that on the phone, and let it out. There was
24 hours of tape and Glyn Johns edited that. It was ten, twenty, takes of
everything as Paul wanted everything rehearsed. The Phil Spector came on
the scene and he was given absolute crap from the recording sessions. He’d
always wanted to work with the Beatles. They did Abbey Road quickly,
putting out something to preserve the myth. As Paul made the suggestion,
John went along, he’s weak as well as strong. Paul wanted to show he was the
Beatles by bringing out the album McCartney. John thinks his new album will
scare Paul into doing something decent, because Paul is capable of doing
great work. But John wishes it was just John, the only one in the world.
P103.