It's not unusual for an artist, designer, or other problem-solver to go to bed thinking about an issue - then wake with the answer. The subconscious mind keeps working, scrabbling away underground.
Sometimes, frankly, it seems as if the ol' subconscious keeps all the good stuff buried - hidden from you - until an idea feels like a little fresh air and strolls upwards to the light of day. Often that's when you're busy but mentally idling - driving, washing dishes, showering, walking, or in those moments between sleeping and waking. Then, if you're not too busy to notice and if you move slowly, not to scare it, you can spot a shy new idea in the underbrush. And catch it!
Public domain image