That is not meant in a literal way, as if it were some biological drive capable of bringing all to completion and which need only develop itself. We strive for perfection, but perfection has no concrete goal. We are in want, we strive, because our completion must remain unfulfilled. Our every movement is innately purposeful, complete, and yet we can never enunciate the purposefulness, completion, and perfection, into any literal goal beforehand. It is a point of view that arises with seeing into one's essential nature.
Perfection is a necessary fiction, a metaphor, or skilful means.
When we realize the goal of perfection toward which we strive as an impossibility in every objective and literal sense, then we also are able to recognize how necessary this fictional perfection is. It is formative of character. Goals are thrown up by our own deep nature as bait to catch the living fish, fictions to instigate and guide action. It is not the defined goal, the stated purpose, the sense of purpose that is fertile. The essential purpose of our Zen way or method is to maintain by it own method that sense of way.