Experience and leverage
I watched a short video of a man demolishing a wall. Half of the wall had already been removed and he was working on the remaining half. As he worked, he swung a long sledge hammer, beating what still stood.
With each blow, the wall moved infinitesimally.
After thirteen swings, another worker entered the scene. He was carrying a long pry bar. He wedged it neatly in the vertical gap between the two adjacent walls. With a nonchalant push, the wall-to-be-removed detached and fell wholly to the floor.
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Our most significant progress comes from understanding leverage and where to push, not from how hard we sweat or how long we bang away at things.