That's always the best feeling. I was building a messaging app once for a college project, and I couldn't get it to work at all. Took it to my instructor after class, explained the issue, and explained all my ideas/attempts to fix it.

He booted the application up on his machine, and it worked first try. Somehow, from that point on, it was working, and I still have no idea how. My only guess is that it was some kind of caching issue.