I don't really know why an idea comes to me. But all of a sudden, an idea comes and from experience I can intuit what something means when an interesting line pops up. Or I can intuit what an interesting choice might be. And I can try a couple of different choices, and see which one feels right, and then continue the song to see where it goes.
Paul SimonAnd so you see I have come to doubt -All that I once held as true ~ I stand alone without beliefs -The only truth I know is you
Paul Simon