It's not a specific hack, but it has given me the same feeling, something I keep discovering: It's just a bunch of rules. Learn the rules and you understand it.

We've probably all seen it with computing; it looks mysterious from the outside but learn the logic and you can make it go.

Fixing cars is the same way (fuel, air, spark). Circuit design is the same way (a few types of component, logic gates). Power engineering is the same way (W = V*A, wire's got to be big enough). Music is generally the same way (very math-y in both the time and frequency domains). Dating is pretty similar (statistics play a different role here, but you can do well enough here "by the book").

We're currently learning that raising a child is the same way. Diaper, hungry, tired, hot/cold, {colic, teething, other age related issues}, doctor.