Taleb tells the story of someone who traded green lumber and made a considerable profit from it, while thinking that green lumber was literally logs painted green, not knowing it was fresh wood. But not knowing this fact did not affect his ability to trade it effectively. So when we assume some information is necessary and important when it really isn’t, we’re committing the green lumber fallacy.

As another formulation, you do not need to understand aerodynamics or physics to ride a bicycle.