The clarity of stepping away...
It's amazing how just taking a few moments to step away from something you are working on can make a big difference in your ability to see it clearly.
Last night, I had been working on a part of the PowerCard code and was unable to get it working... I struggled with it for perhaps 20 - 30 minutes, then finally, gave up and went to bed.
This morning, I found the problem in 15 seconds from opening the project.