Basically, it's similar to "the student becomes the teacher". One day, you'll start out learning how to write essays, and in the future, you might teach others how to do it. It means that the more you learn and experience, the more knowledge you'll be able to pass onto someone else.
You could write an essay that argues that the more you learn and experience, the more you'll have to teach, and include examples of people who contributed to accomplishments in history and that they too began as a "learner" and not the teacher or the master they're considered.
Rhetoric is the art of discourse, an art that aims to improve the capability of writers or speakers to inform, most likely to persuade, or motivate particular audiences in specific situations. As a subject of formal study and a productive civic practice, rhetoric has played a central role in the European tradition.<span>Its best known definition comes from </span>Aristotle, who considers it a counterpart of both logic and politics, and calls it "the faculty of observing in any given case the available means of persuasion<span>."</span>