I liked others' comments as well that "perfect" etymologically means "complete" (as distinct from "flawless"), and that a living organism is never and can never be complete.
I've been studying biology, and it is in the basic structure of living organisms that they can only either (1) grow / move forward, (2) go into deep hibernation, or (3) decline and die. Only with the latter two directions does the organism reach some semblance of completeness.
A growing organism is incomplete, and incapable of being complete. It always has more work to do on its own being: more to be integrated, acquired, learned, decided, built, pumped, changed or disposed of - from the highest levels of its knowledge and behavior, down to physical, sub-cellular and molecular levels.
Perhaps risking controversy, I must submit here that the very notion of "moral perfection" is baggage left over from Platonism or the Morality of Death, and is not compatible with a Morality of Life. I believe Rand understood that partially, but not, um, perfectly.
Since it is baggage from the Morality of Death, it has negative effects. A person who says "I am morally perfect" commits himself to that conclusion, and thus gives himself an incentive - of whatever size - to evade contrary information that may otherwise benefit his life. He also increases his focus (i.e., beyond what is useful and required) on *tracking and evaluating status* - taking more than is required from his focus on other cognition, production, rest, enjoyment, etc.
Because "complete" means "dead" (or deeply hibernating), when speaking of life: the person who says "I am morally perfect" says, without knowing or intending to, "I am morally dead." I do not believe Rand fully understood this, as an implication of her Morality of Life and life's inherent nature.
Morality is a tool for humans to employ in making more beneficial / profitable choices. Is it worth one's time, or even intelligible, to speak of a state of perfection with any tool? For example, "hammer perfection"? "Buzzsaw perfection"? "Piano perfection"?
To strive for a high level of skill, knowledge and integration with a good tool is worthwhile indeed. And one will always find more to discover or create or integrate, no matter what level of skill one reaches. And one will always make more mistakes as well; the master simply recognizes and recovers from her mistakes faster.
I apologize for length, and for echoing many points made earlier. I've been stuck on the question before and found it useful to work these things out in my own words.
(Edited by Jeff Carty on 9/12, 2:53pm)