[CatMtKing]

I practice taijiquan, a martial art. My teacher often describes concepts that I can relate to basic mechanics. When I do, it feels like I understand, but as my teacher says -- until you can actually express it with your body, you don't really understand.

For example, a lever seems conceptually simple, but to create a lever in the body is extraordinarily hard. The joints have to be solidly connected and free to open or close. The direction must be precise and rotation must not wobble. There are so many things that can err and lots of places for force to leak out.