I'm sure this is some sort of idiomatic expression, I just don't know exactly what it means. Searched everywhere but didn't find anything.
Sometimes the "Gijutsu" part is replaced by another thing, so I suppose the rest of the expression is the important bit.
To clarify, I know the literal meaning of the sentence "Technique isn't something you learn, it's something you steal". I just don't know what the expression entails.