Motorcycle maintenance.

I've wondered why it took us so long to catch on. We saw it and yet we didn't see it. Or rather we were trained not to see it. Conned, perhaps, into thinking that the real action was metropolitan and all this was just boring hinterland. It was a puzzling thing. The truth knocks on the door and you say, "Go away, I'm looking for the truth," and so it goes away. Puzzling.

-Pirsig