Here's the link for part 2 (and here's part 1).
"There's a scenario when I could look at The Beatles' career and think, 'Wait a minute, we are talking Eleanor Rigby, Blackbird, Hey Jude and Let It Be. I've probably written my best song so you've got to give up.'
"At that point you say, 'Thank you very much,' and go on a long holiday'.
"But I love music too much. There's always this thought in the back of my mind that... well, you never know.
"I might just come up with something else really good. That keeps you going."