I'm glad the feeling comes in difficult endeavors that you think you can make your way through.
Paul Simon said he gets a satisfied feeling by writing songs that never comes in any other parts of his life. Susan Shaughnessy said of writing books --- or in writing long narratives, I guess, distinguishing from songwriting --- that you get the sense of a breakthrough coming.
I've only finished one novel, start to finish. I have to admit there was, or, perhaps, there were times when I felt a breakthrough was coming and had other senses of insight and ways of getting through a forest when I felt lost in the dense trees and brush. It was nice to have the feeling or the sense that you could break through. But that all didn't finish the work or make it any easier to stick to it and fight through it. Sometimes the underbrush had to be hacked away.