You might write down 10 stupid things and then have a hit on the 11th. And you'd never have gotten to that one if you hadn't worked through the first 10. I don't try to completely flesh an idea out, but just write two or three words. And then I go back later and expand on it. Or I might find a note months from now that didn't work then, but works with something I'm doing now.
People tend to procrastinate, and leave routines hanging as just looses strands of ideas.
You don't even have to consider it a failure, but rather a trial and error on the way to getting closer to what you want. I think creativity is a discipline. It only took a couple of years until I realized I needed to create a volume on every subject. I'm going to have to keep having ideas for a long time to stay in the business. And once you you forgive yourself for writing down stupid things, it becomes an approachable, fun thing to do.