Sir Paul McCartney thinks songwriting is like "talking to a psychiatrist".
The Beatles legend still gets a "buzz" when he writes a new track and finds it incredibly useful to be able to pour his troubles out into new lyrics.
He said: "I still get the same buzz from songwriting. There’s a black hole. There’s nothing there. And you start going da-da dum-di-dum-di, and there’s suddenly a song. Sometimes it’s like talking to a psychiatrist, because you’ve got your troubles out. You feel satisfied."
The 77-year-old musician also finds it easier to reveal his "awkward truths" and "innermost thoughts" in his lyrics than to speak about them directly.
He admitted: "In private life, I don’t want people to know my innermost thoughts. A song: that’s the place for them.
"Like in ‘Here Today’, when I’m saying to John [Lennon], ‘I love you.’ I couldn’t have said that really to him unless we were extremely drunk.
"But you find you can put these emotions and these deeper truths and sometimes awkward truths in a song, whereas it’d sound daft if you’d just said it. That’s one of the things I like about songs."
While Paul likes to jot down ideas for songs as he’s going about everyday life, he admitted there is a "danger" to the approach as it’s left him with "millions" of snippets of music that he’s never finished.
Speaking on BBC Sounds’ ‘Mastertapes Guide to Writing the Perfect Song’, he said: "Having recording devices in your pocket is such a danger. If I get an idea, I’ll grab the cassette, hum a bit, think, ‘I’ll finish that later.’
"I’ve got millions of cassettes, full of snippets I’ve hummed. Where did I want that one to go? You say you’ll finish it later but you never do."