All the people I've ever met seem whom I'd consider in the genius category seem to share this trait. They see ordinary things that everyone else overlooks and wonder about them in a playful and curious way. Plates wobbling, apples falling from trees, or even as PG so eloquently put it, "looking at Maxwell's equations and saying, what the hell is going on here?"

Its like driving a wedge into a tiny crack in the unknown and splitting it open to reveal all of the cool stuff.