Today I was listening to three teenage boys discuss the unrealistic admonition to fall forward without using your hands to break the fall. As anyone who has suffered a broken wrist after falling knows, it's not in our biology to roll without putting our hands out first.
We naturally extend our arms, palms out, to protect ourselves from a painful or overwhelming experience, whether it is to say "No, you can't tell me that," or to grasp the moment that "Is too wonderful for words." Doing anything different is against our natures as human beings.
So why do so many people give the advice that we must "write what we know"? This limits us as writers, and allows others to believe that they are being sage rather than pedantic.
Our first instinct as writers must be the one that drives us to unearth the unknown within the known. And, yes, we may break a few ancient bones in the process, but it's the only way to push back against the restrictions inherent in the "rules" of writing.