That's how writing is, too. For weeks and weeks I've been struggling with a specific problem in a new proposal I'm working on, turning it over and over in my mind, hitting road-blocks every time I try to figure out a way to go forward. In the meantime I've been working on plot development and character arc and various other things, but this problem was significant enough to prevent me from making any major inroads into the story.
Okay, here comes the good news: yesterday as I was running, the solution just occurred to me. It was the most incredible feeling--suddenly it was like this big, messy fog had just lifted, leaving a perfectly clear view. Yay! A very big wall has come down and I can actually go full speed ahead, instead of creeping forward by inches and degrees, which is what it has felt like for close to a month.
Or at least, I'll go full speed ahead...until I hit that next wall. Then I'll start the creeping, crawling process of scraping my way above and around it, until the next open vista comes into view...etc etc etc. It's endless; but that's writing.