adept
Very skilled and good at doing something difficult.
Adept means highly skilled at something. An adept pianist can play complex pieces smoothly because they've spent years mastering their instrument. A student who's adept at math doesn't just know the formulas: they understand how numbers work together and can solve tricky problems with confidence.
Someone who's adept has moved beyond just following instructions to really understanding their craft. A chef adept at baking doesn't need to constantly check recipes; their hands seem to know exactly how the dough should feel. A basketball player adept at free throws has practiced so many times that sinking the shot feels natural.