To celebrate his 90th birthday, the NY TIMES re-published a 2017 interview of lyricist Stephen Sondheim by playwright Lin Manuel Miranda, which included this bit of creative advice:
Sondheim: ...you know, it’s the old lesson, you’ve got to work on something dangerous. You have to work on something that makes you uncertain. Something that makes you doubt yourself.
Miranda: Talk a bit about that danger and uncertainty.
Sondheim: Well, because it stimulates you to do things you haven’t done before. The whole thing is if you know where you’re going, you’ve gone, as the poet says. And that’s death.